Annoying windows messages

Does Anyone know how to stop this? each time i open a folder in my local disk it says "System error! Attention owner! some dangerous trojan horses detected in your system. Microsoft windows xp files corrupted. this may lead to destruction of important files in C:/windows. download protection software now!

Click OK to download antispyware. (Recommended)" what the hell?? i press no and it redirects me to some dodgy free scan of my computer on a browser... i've ran scans on avg and Spybot and nothing comes up.. anyone know how to stop this???? here are some screenies of what i went though... hxxp://s277.photobucket.com/albums/kk41/voidwalker_2008/?action=view&current=WTFLIEEESSS.jpg
hxxp://s277.photobucket.com/albums/kk41/voidwalker_2008/?action=view&current=wtflieeeeessss.jpg

 

Hi john117,
Welcome to Major Geeks!

The scans you used were not adequate to locate the problem. Please go through the READ & RUN ME FIRST and attach the requested logs so we can see what's causing the problem and give you specific instructions for getting rid of it.

Thanks.
abri