Everything has a problem and needs to close but works if not. Help!

Okay, a major problem has hit my beloved computer that is agonizing the crap out of me and I seem to be on my wits end. The problem that happens is the following: As I go in windows everything seems to work just fine until any programs start to boot up. Then suddenly a problem comes to the screen telling me that "'insert name of program running" has a problem and needs to close."
then there is the option of Send a report or not send. If I ignore this window the program works fine, now this isn't a local problem with one program no, it's for every single program on the computer, from Gmail notifier to games like Half Life 2. Not a single program on my computer run without the Problem box of evilness comes up telling me that it has gotten a problem. Of course I suspected a virus or malware having fun with me so I searched with several programs but I find nothing. So I try registry cleaning and nothing. Rebooting several times but the same problem persists. When did this problem happen I can infact guide you through incase that might help you diagonalize the problem and hopefully tell me how to fix it without reformating my computer:

After I downloaded Spyware doctor it worked fine and scanned my computer for possible threats. Then I logged in to my other account on the computer and suddenly I got a notice of a script error. So of course I investigated this and found this web site http://www.pctools.com/contact/support/
And then I ran the software that they introduced and tried seeing if the Spyware doctor would work but no it didn't. I then rebooted my computer in hope THAT would fix that problem but no, instead I got that problem that I have now. I'm running on a Windows XP. Hopefully Somebody can help me, Thanks for your time.