Lately, my computer has started acting really strange, to say the least. After it's been on for a while, I'll notice that all of my programs will start acting differently. Without fail, every time my computer has been on for a few hours or so, I'll click on the start button, and the icons will show up, as well as the text (photoshop, notepad, etc), but as I run my mouse over them, the text will disappear, and then most of websites, and dialogs within programs will be jumbled... For instance, if I try to save a bookmark, there will be only symbols, and no real text that means anything, or, sometimes, no text at all, just buttons and spaces where text should be. Also, my antivirus (Active Virus Shield) will disable, and I won't be able to open any programs after that all happens. Any ideas as to what could be happening? Thanks in advance for the help, I'm usually pretty good with computer stuff, but this has totally baffled me.
--Matt

Sounds like spyware to me. Do u have a anti spyware program running?

agree with mayers57, run trojan remover, link - http://www.simplysup.com/, and run a good antivirus in safemode (nod32 or kaspersky).