My Windows XP is highly bugged.

Last night after checking myspace and listening to some music from it my computer started to act really odd, for example, Firefox suddenly shut down and said that there was an illegal operation about some plug-in, it kept doing this on and on. Then most of my usual software such as Windows Live Messenger, my antivirus (AVG) and my older firewall (Comodo). Apparently most of my programs are corrupted and lately when I try to load a webpage from firefox it won't work or it takes too much time to load the pages (Same happens with Internet Explorer). It also kept popping up the alert message of Low Virtual Memory several times and showing me a 100% of CPU usage most of the time. Another weird fact that happens is that the PC shuts off by itself every single hour.

I don't really know what's going on and this is a Toshiba brand computer, to be more specific a Toshiba Satellite A85-S107/S1071 with Windows XP Home Edition installed in it. Any help will be greatly appreciated.

 

Welcome to Major Geeks! For starters, I'd say you have malware in addition to some fairly serious Windows problems. If there's nothing important on the PC you need to save and you have a restore disc or a Windows CD, formatting a installing Windows clean might be something to think about. If that's not possible or more of a last resort, try some general maintenance first (read this http://forums.majorgeeks.com/showthread.php?t=106650). Then move on to virus/spyware removal (read this http://forums.majorgeeks.com/showthread.php?t=35407). After following all the steps in both of those links, post again with any symptoms you might still have and we'll go from there.
Good luck!
:major
[dlb]