USB shutting computer down - computer no longer receptive?

Okay.. just so you know, I'm writing this using my laptop.
So for some time, I've been having issues with the USB ports on my desktop computer, to cut a long story short: if I were to plug a USB cable in, such as the one for my webcam, it would crash my mouse & keyboard. Yesterday, I plugged in the USB cable to my digital SLR camera (it wasn't even connected to the camera when I plugged it in...) and my computer completely shut down. Now, whenever I 'turn it on', the fans are working etc, but it is not receptive. The monitor only shows 'Attention: No video input', the CD drive doesn't open on the computer tower and it also doesn't shut down if I hold the power button in. The only way I can shut it down is to switch off the main plug outlet. Is there anything anybody can tell me to help me with this situation? Has the computer just completely died on me now? It is 3 years-ish old... thanks for any help in advance.

Please keep in mind that I cannot currently use the desktop computer. That is my problem, it will not boot up correctly. When I turn it on, to my knowledge the only thing which is functioning is the fans, because the computer does not boot up as usual..

It sounds like you need to install the chipset driver for your motherboard. The big question is where the driver went in the first place, since you obviously used to have it. Start at the top of this list. Install the products one at a time. After you install each one, be sure to install all of their updates. Have each one complete a full scan before proceeding to the next one. One of these *should* fix your problem. Work down the list until your problem disappears. Keep in mind that everyone of these things is either free of charge or open source. That also means that the updates are free. Running the software with out the updates is the same as not running it at all. In addition to anti-virus software, you should also have anti-spyware software.

You should use more than one anti-spyware package because there is no one spyware package that will detect everything. Each one will pick up things that the others miss. Part of this is based on what gets submitted to the people who make the software which in turn is based on what the users encounter. There are so many that its hard to create a comprehensive list of everything out there that spies on you.

When you're done, be sure to go to Windows Update and apply ALL of the patches. Don't just run the "Express" updates. Run "Custom" and pick all of the software that's available to you. It make take several times before you no longer have patches. Once that's done, be sure to turn on your automatic updates. For Windows XP - http://support.microsoft.com/kb/306525. For Vista - http://www.microsoft.com/protect/compute...

Make sure that you're not running a cracked version of Windows or other software packages. Software doesn't get cracked for the benefit of humanity. It gets cracked because a hacker somewhere wants you run his software on your computer. That means he can use your computer to serve porn and send spam. Or capture your user names and passwords for identity theft.

1) Spybot Search & Destroy http://www.safer-networking.org/en/index...

2) Windows Defender - http://www.microsoft.com/athome/security...

3) Lavasoft Adware - http://www.lavasoftusa.com/products/ad_a...

4) Clamwin Antivirus - http://www.clamwin.com/

5) Fsecure Black Light - http://www.f-secure.com/blacklight/