Taskbar Constantly Freezing

Well like starting this year I had some problems with my pc, involving the taskbar, at first when I logged on to windows the taskbar wouldnt load for some reason, I solved that using the first two methods from this microsoft page
http://support.microsoft.com/kb/318027/en-us

Now that that was fixed, then the taskbar would start freezing all of the sudden, when I clicked start or when I clicked one of the buttons from the quickstart bar, this was supossed to be fixed by this
http://support.microsoft.com/kb/841571/en-us

It did for a while, but then it came back, I barely get a chance to open firefox, and when the taskbar is frozen I cant even open the taskbar manager or do any other activities other than the ones that are already opened. It would usually just freeze for a while, I would give it just a minute or two and then it would go back to normal, but now It doesnt, I gotta restart the pc, and if I try to log off, the little windows stays at 'saving settings' and thats it, I have to turn it off my self.
I already tried fixing the windows but theres no option to repair when I use my Windows XP Pro CD
I am on my bro's computer posting this atm.

any Ideas on how to fix this?
Id really appreciate some help guys.

 

Thanks dude that site really helped me, I went thru some of my active services and apparently the AVG antivirus was the problem, the moment I got the popup saying the database was out of date it froze, Ithanks ^_^