Dear Sushant don’t panic. Nothing will be lost, you may get all of your data, just keep your mind and brain cool….. There are a number of reasons why this may have occurred!
NOTE: Before doing anything you must take all necessary data backups else it may cause serious problems.
- The particular computer may affect by virus
- It is possible one or more service(s) may stop suddenly
- Corrupt any system related files
- All of a sudden other 3rd party software may creates problems
First you have to disconnect the particular affected computer from your network.
Now check one by one (as told earlier), you may use in-built system checker tools or licensed utility software to find out the problems. Though you didn’t disclose which OS your using, I guess you may know how to use these tools of software.
I disagree that this has anything to do with a virus.
Your symptoms are more indicative of a layer 2 (data-link layer) issue, not of any applications or services (viruses or otherwise).
If the network is fine without the PC plugged in, and cabling it in almost IMMEDIATELY crashes EVERYONE’S network connection, you my friend have a bad NIC on that PC.
The NIC, when connected, is trying to contact a DHCP server, which is a BROADCAST packet in IPv4, and the fact that the ENTIRE network drops means you’re experiencing what we call a “Broadcast Storm”
Easy fix: Replace the NIC in the PC and try again.