This operating system was the first, that was installed on personal computers widely, Bill Gates (Microsoft Corporation) firstly developed PC-Dos for IMB, then he got its rights for its new version MS-Dos. DOS was a non-graphical interface not friendly like Windows operating systems, and basically work on commands, now a days Windows operating system still support DOS interface for special tasks, and it provide the DOS non-graphical interface.
Find MAC address of LAN computer
Get MAC Addres of a compute on LAN
Goto start and Run
type Cmd
and at Dos prompt type
Ping xxx.xxx.xxx.xxx (Ip address of the computer you want to get its MAC address)
when you get the reply
type arp -a
It will show you MAC address under the physical address
Goto start and Run
type Cmd
and at Dos prompt type
Ping xxx.xxx.xxx.xxx (Ip address of the computer you want to get its MAC address)
when you get the reply
type arp -a
It will show you MAC address under the physical address
Delete Temporary Files
Goto Run
Type %temp%
Press Ctrl + A (To select all files)
then press delete or
Hold down the Shift key + Del to delete all files directly without send them to recycle bin
Type %temp%
Press Ctrl + A (To select all files)
then press delete or
Hold down the Shift key + Del to delete all files directly without send them to recycle bin
System Properties (Enable, Disable)
If you want to disable or unable System Properties option. Go to start and type Regedit and press enter. Go to the following registry key. Hkey_Current_User \ Software \ Microsoft \ Windows \ Currentversion \ Policies \ Explorer Modify/ then create dword data type Reg_Dword and name it (nopropertiesmycomputer)
(0 is use to show the properties / 1 is use to hide the system properties) save settings exit from registry and restart your computer.
ROM
ROM stands for Read Only Memory. ROM is a permanent memory even when you shutdown the computer, the configuration in ROM will remain in memory, the primary purpose of ROM is to tell the computer whenever it starts that how you run the operating system in RAM, it tells the computer about boot sequence, at start up, it checks the hardware, this is a permanent memory in computer, but you can upgrade it by changing the chip physically, but you can also upgrade firmware through software.
CMOS
CMOS or Complementary Metal Oxide Semiconductor which is on computers mother board, the purpose of that bettery is to supply power to BIOS in which system date, time and other system configurations are stored.
RAM
When we start computer, the operating system file are store in RAM, RAM is a temporary memory where files are stored and when we shutdown our computer this mamory become washout. Suppose if you play a game and run the executibale files of game, these files goes to RAM and it runs from RAM, after quiting from game, the computer can remove the unnecessary files from RAM, so that other files can place in RAM, thus if you need to speed up your computer then more RAM is required for it. If you have more RAM your processor will be free for other tasks because it will not process your requests again and again from hard drives, another reason is that, that the speed of reading and writing RAM is fast than the Harddrive. The BIOS also run your start up files in RAM during boot process. There are several types of RAMs in market, such as SDR (Single Data Rate) is the older one, after that DDR, DDR2 & DDR3 are the new ones, which supprt greater speed than SDR, if you use one type of RAM then it will not work with the other type of RAM you must be pluged both of the RAMs as the same type.
BIOS
BIOS
Basic Input Output System or BIOS is a program (firmware), it controls your computer when it start till you shutdown the Computer, when you on the computer BIOS program check all of your hardware called POST (power on self test) and then it load the operating system files into your RAM. BIOS also look to your data and manage it when it is moves to different hardware of your computer. BIOS also manage Date of time of your computer in a chip Complementary Metal Oxide Semiconductor) CMOS. Its necessary that you can update your BIOS, because after the new hardwares came in market some older chips do not support new hards, so it needed to be updated it.
Basic Input Output System or BIOS is a program (firmware), it controls your computer when it start till you shutdown the Computer, when you on the computer BIOS program check all of your hardware called POST (power on self test) and then it load the operating system files into your RAM. BIOS also look to your data and manage it when it is moves to different hardware of your computer. BIOS also manage Date of time of your computer in a chip Complementary Metal Oxide Semiconductor) CMOS. Its necessary that you can update your BIOS, because after the new hardwares came in market some older chips do not support new hards, so it needed to be updated it.
Computer Viruses
Computer Viruses, Trojans, & Worms:-
Computer virus is a program that is man made, this programm is always hidden in your files and folders, the computer viruses destroy your data, slow down your computers, and change the default settings of your computers, it creat copies automatically and thus the viruses spread from computer to computer through memory cards, and USBs etc when you transfer data in these media. There are 2 types of viruses macro viruses and worms viruses.
Macro:-
Macro viruses are small programs that are oftenly attached with a file, suppose if you create a file in MS word, that macro virus will be attached with that file and when you copy or move the file the file will be copy attached with it, and thus it will spreed like this, this type of codes effects the program in which the file is created, if you creat a file in MS word, then this virus will effect MS word, its effect depends on what type of codes it has. Macro viruses always attached with files that are created in MS Office like programs and not with executiable files. Macro viruses spreed very fastly because due to the removeable media files are copied and movied easly.
Boot sector viruses:-
Boot sector viruses is the dangours virus which resids in the Master Boot Record or Dos Boot Sector, as you know the MBR control the sequence when the computers start, it tells the computer that in which partition the operating system reside. Thus if a Boot Sector Visrus infect your MBR or Dos Boot Sector it will run automatically when ever you start your computer and when it infect your memory the antiviruses hardly detect it. And from there this virus spreed in every drive you can read, if you want to remove viruses like this then you must use the antiviruses bootable disk to start computer from these disk and then run antivirus to detect it.
Worms:-
The worms are small coding programs, they are too consideres as viruses because they they few similarities with viruses, they irrupt computer functions or a computer programs, but the mail diferrence is that they do not attached himself with files but they reside in computer seperately and from their they effect the computers.
Fiber Distributed Data Inteface FDDI
Fiber Distributed Data Interface (FDDI):-
FDDI technology have many features same with the Token Ring, but its data transmission speed is high and it transmit data on the speed of 100Mbps, in this network we use Ring Topology rather than Star, in this technology if one ring is physical damage then the computers in this network uses the other ring. It supports 500 nodes, and supports double Ring Star Topology.
FDDI technology have many features same with the Token Ring, but its data transmission speed is high and it transmit data on the speed of 100Mbps, in this network we use Ring Topology rather than Star, in this technology if one ring is physical damage then the computers in this network uses the other ring. It supports 500 nodes, and supports double Ring Star Topology.
Wireless (802.11b)
Wireless (802.11b):-
This network works on 2.4Ghz frequency with 11MB using Radio signals, in this network the NIC (Network Interface Card) connected with access point through signals, and this access point transmit signals to every NIC card that is part of that network, thus this access point works as a hub, this access point also support the wired Ethernet and both wireless and wired computers both worked together, its maximum range is 50 to 300 feet but you can extend it through wireless devices, such an antenna etc.
This network works on 2.4Ghz frequency with 11MB using Radio signals, in this network the NIC (Network Interface Card) connected with access point through signals, and this access point transmit signals to every NIC card that is part of that network, thus this access point works as a hub, this access point also support the wired Ethernet and both wireless and wired computers both worked together, its maximum range is 50 to 300 feet but you can extend it through wireless devices, such an antenna etc.
Token Ring (802.5)
Token Ring (802.5)
In Token Ring network a computer sends a token, this token passes through every computer which is part of the network but only the destination computer accepts the Token, during this time no other computer can send Token in network but wait until the network’s media becomes free, in this type of network the computers must be connected with the media in continues loop form. Through Token Ring network you can install long distance network. In Token Ring if a Token is lost then the protocol regenerate the Token after the specified interval elapsed. This type of network support 255 nodes.
In Token Ring network a computer sends a token, this token passes through every computer which is part of the network but only the destination computer accepts the Token, during this time no other computer can send Token in network but wait until the network’s media becomes free, in this type of network the computers must be connected with the media in continues loop form. Through Token Ring network you can install long distance network. In Token Ring if a Token is lost then the protocol regenerate the Token after the specified interval elapsed. This type of network support 255 nodes.
5-4-3 Rule
5 4 3 rule:-
5-4-3 rules mean that in your network you must have 5 segments of cables, with 4 repeaters, and that network must be 3 or less mixing segments. Its mean that if you have a network with coaxial cable’s network, then you must be 3 segments of 500m for 10Base5 and 185m for 10Base2 in your network with computers that will be connected with 2 repeaters. You can extend this type of network by installing 2 repeaters and 2 segment of 500m and 185m of cables.
If we talk about 10Base2 network in which we use BNC (British Novell Connector) with RG-58 cables, and Bus Topology, in this network we extend our network up to 925m and in 10Base5 network you can use up to 2500m, in this situation you can use only 5 segment of cables with 4 repeaters that connect these 5 cables with each other in a series and only 3 segments must be included computers and other devices. Half-meter is the minimum length of cable between computers, the BNC connector must be ended with terminator, you can put 30 computers on each segment, remember that the total length of all 5 segments must not be extended from 925m.
5-4-3 rules mean that in your network you must have 5 segments of cables, with 4 repeaters, and that network must be 3 or less mixing segments. Its mean that if you have a network with coaxial cable’s network, then you must be 3 segments of 500m for 10Base5 and 185m for 10Base2 in your network with computers that will be connected with 2 repeaters. You can extend this type of network by installing 2 repeaters and 2 segment of 500m and 185m of cables.
If we talk about 10Base2 network in which we use BNC (British Novell Connector) with RG-58 cables, and Bus Topology, in this network we extend our network up to 925m and in 10Base5 network you can use up to 2500m, in this situation you can use only 5 segment of cables with 4 repeaters that connect these 5 cables with each other in a series and only 3 segments must be included computers and other devices. Half-meter is the minimum length of cable between computers, the BNC connector must be ended with terminator, you can put 30 computers on each segment, remember that the total length of all 5 segments must not be extended from 925m.
How to Test Network Media
After the installation of network you must check all the media through which we connected the network computers and other devices. The maintenance of your network is continues process.
Ping Command:-
Ping command is the easiest way to check your protocols, your Ethernet Cards, network cables and other means through which our peripherals are connected. When you apply ping command send a packet to the destination address and waits for reply, when it receives a reply from destination its mean that your protocols, LAN cards, network cables and network connects are working properly. There are several versions of Ping command. The ping command shows you the RTT (Round Trip Time) which means that in how much time ping command get back the packets. It will show you the packets that was lost, which mean that there are some problem in your media. It also shows you the duplicate, dropped and reordered packets.Also remember that the ping command did not show you that why the packet is delay, why it is damage, or why is it duplicate nor it show you that where is the problem. Ping command will not show you the reason why the packets are un-answered.
Functions used with Ping command:-
-f
If you use the function –F with Ping command it will send packets very fast to the destination, with the speed of 100 per second, it will slow down your network, because it like a flood in your network, to test your media. This is a good idea to use that command when your network will not busy.
-l (Pre-load)
Send packets very fast and then in normal, this is useful command when you want to check the performance of your router, that how your router handle these packets.
-n
When you have Name Server problems then use that function.
-r
Use this function if you have routing problem and during ping command it cant reached the destination, this command is used where host and destination connected directly without routers.
Ping Command:-
Ping command is the easiest way to check your protocols, your Ethernet Cards, network cables and other means through which our peripherals are connected. When you apply ping command send a packet to the destination address and waits for reply, when it receives a reply from destination its mean that your protocols, LAN cards, network cables and network connects are working properly. There are several versions of Ping command. The ping command shows you the RTT (Round Trip Time) which means that in how much time ping command get back the packets. It will show you the packets that was lost, which mean that there are some problem in your media. It also shows you the duplicate, dropped and reordered packets.Also remember that the ping command did not show you that why the packet is delay, why it is damage, or why is it duplicate nor it show you that where is the problem. Ping command will not show you the reason why the packets are un-answered.
Functions used with Ping command:-
-f
If you use the function –F with Ping command it will send packets very fast to the destination, with the speed of 100 per second, it will slow down your network, because it like a flood in your network, to test your media. This is a good idea to use that command when your network will not busy.
-l (Pre-load)
Send packets very fast and then in normal, this is useful command when you want to check the performance of your router, that how your router handle these packets.
-n
When you have Name Server problems then use that function.
-r
Use this function if you have routing problem and during ping command it cant reached the destination, this command is used where host and destination connected directly without routers.
IEEE 802.5 Standards
10Base-5:-
Support Coaxial (RG-58A/U), use in Bus Topology, with 500m of Cable in length, with the speed of 10Mbps.
10base-2:-
Support Thin coaxial (RG-58A/U), use in Bus Topology, with 185m of Cable in length, with the speed of 10Mbps.
10Base-T:-
Support UTP (unshielded twisted pair of cat 3), use in star Topology, with 100m of Cable in length, with the speed of 10Mbps.
1Base-5:-
Support UTP (unshielded twisted pair of cat 3 and above all), use in Star Topology in which simple repeaters and hubs are used, with 100m of Cable in length, with the speed of 1Mbps.
10Broad-36:-
Support Coaxial (RG-58A/U, cat v), use in bus Topology, with 3600m of Cable in length, with the speed of 10Mbps.
10Base-FL:-
Support Fiber optic (Multimode 62.5.125 Fiber), use in Star Topology, with 2000m of full duplex Cable in length, with the speed of 10Mbps.
100Base-TX:-
Support UTP (Cat 5), use in Star Topology, with 100m of Cable in length, with the speed of 100Mbps.
100Base-FX:-
Support Fiber optic (Multimode 62.5/ 125 Fiber), use in Star Topology, with 412m (Half-Duplex) and 2000m (Full Duplex) of Cable in length, with the speed of 100Mbps in Half-Duplex and 200Mbps in Full-Duplex.
1000Base-SX:-
Support Fiber-optic (62.5/ 125 fiber), use in Star Topology, with 260m of Cable in length, with the speed of 1Gbps.
1000Base-LX:-
Support Fiber-optic (multimode 62.5/ 125 fiber) or mono mode fiber, use in Star Topology, with 440m (multimode) 5000m (single mode) of Cable in length, with the speed of 1Gbps.
1000Base-CX:-
Support Twinax, 150 ohm-balanced, shielded cable, use in Star Topology, with 25m of Cable in length, with the speed of 1Gbps.
1000Base-T:-
Support Cat 5, use in Star Topology, with 100m of Cable in length, with the speed of 1Gbps.
Note:-
1. 10 shows the speed of data which is travel in the media, 10 mean that the data will be transfer with the speed of 10 Megabits / Second (10Mbps)
2. Base is the short from of Baseband which signify the network’s type.
3. The segment length must be in digit, and segment type must be in letter form.
4. If a cable belongs to 10Base5 family, then the maximum cable length must not be exceeded from 500 meters.
5. Letters show that if a cable belongs to 10BaseT family then T means Twisted-Pair.
Support Coaxial (RG-58A/U), use in Bus Topology, with 500m of Cable in length, with the speed of 10Mbps.
10base-2:-
Support Thin coaxial (RG-58A/U), use in Bus Topology, with 185m of Cable in length, with the speed of 10Mbps.
10Base-T:-
Support UTP (unshielded twisted pair of cat 3), use in star Topology, with 100m of Cable in length, with the speed of 10Mbps.
1Base-5:-
Support UTP (unshielded twisted pair of cat 3 and above all), use in Star Topology in which simple repeaters and hubs are used, with 100m of Cable in length, with the speed of 1Mbps.
10Broad-36:-
Support Coaxial (RG-58A/U, cat v), use in bus Topology, with 3600m of Cable in length, with the speed of 10Mbps.
10Base-FL:-
Support Fiber optic (Multimode 62.5.125 Fiber), use in Star Topology, with 2000m of full duplex Cable in length, with the speed of 10Mbps.
100Base-TX:-
Support UTP (Cat 5), use in Star Topology, with 100m of Cable in length, with the speed of 100Mbps.
100Base-FX:-
Support Fiber optic (Multimode 62.5/ 125 Fiber), use in Star Topology, with 412m (Half-Duplex) and 2000m (Full Duplex) of Cable in length, with the speed of 100Mbps in Half-Duplex and 200Mbps in Full-Duplex.
1000Base-SX:-
Support Fiber-optic (62.5/ 125 fiber), use in Star Topology, with 260m of Cable in length, with the speed of 1Gbps.
1000Base-LX:-
Support Fiber-optic (multimode 62.5/ 125 fiber) or mono mode fiber, use in Star Topology, with 440m (multimode) 5000m (single mode) of Cable in length, with the speed of 1Gbps.
1000Base-CX:-
Support Twinax, 150 ohm-balanced, shielded cable, use in Star Topology, with 25m of Cable in length, with the speed of 1Gbps.
1000Base-T:-
Support Cat 5, use in Star Topology, with 100m of Cable in length, with the speed of 1Gbps.
Note:-
1. 10 shows the speed of data which is travel in the media, 10 mean that the data will be transfer with the speed of 10 Megabits / Second (10Mbps)
2. Base is the short from of Baseband which signify the network’s type.
3. The segment length must be in digit, and segment type must be in letter form.
4. If a cable belongs to 10Base5 family, then the maximum cable length must not be exceeded from 500 meters.
5. Letters show that if a cable belongs to 10BaseT family then T means Twisted-Pair.
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