Internet Explorer losing connection and displaying weird mess...help?

[Leem]

I've been experiencing a strange vista problems for maybe a month or two after some windows updates, prior to that everyone was working perfectly. The problem seems to occur after playing games such as World of Warcraft for a long period of time, after I would quit out of the game I would lose all internet connectivity but I could ping servers like google, if I tried to open up a webpage I would get the bizaare mess in the screenshot, if I tried to use the taskbar I would get the message "Logon failed to create the security Dialogue" Since then, i've done several fixes and at least, that message no longer appears and I can reboot normally.

After checking and doing research for the past month and eliminated possible faults such as memory, i've done testing with vista and X86 mem test, all passed. I've done research using event viewer, an often error was WMI error 15007, I followed the steps to correct it from various websites and no longer have the error but the problem still occurs but less frequently than before and the "Logon failed" message no longer appears though and I can restart the computer without switching it off the hard way..

But my question is, what would cause IE to seriously mess up like that? I've currently got very little installed on the computer, basically zonealarm, avast and world of warcraft. I've since switched to Firefox and instead when this error happens, on FF I get the error "Content Encoding Error" and if I immediately switch to IE, I get the bizarre mess in the screenshot that I posted, its very very annoying and i'd love some help, i've pretty much exhausted every means of testing possible, as far as I can tell, my computer is in good health, so it could possibly be errors with world of warcraft, but its never done it before.

As you can see, internet explorer displaying a mess....

[Leem]

Also, I've done all possible motherboard/networking driver updates possible, everything I can find has the very latest updates that I can find. I can't find much information on error code 15007 either, some sites say that's vista saying its invalid/pirated. I'm running a legit/activated copy that came with my computer, I brought it from cyberpowerpc back in June 08', it worked flawlessly until around November time after some updates, It initially got so bad that I had to reinstall vista but the problem still occurred but at least, its bearable at the moment but still, I would like to solve and fix this problem for good.