Please help someone, this will be quick

I am seriously frustrated with this computer. I have obtained every virus,spy,and program out there. My computer thank god runs quicker and seemingly more efficiently. HOWEVER, certain websites do not work and IE 7 and 6 dont work properly. I cannot check email but I can go to outlook. I cannot sign on to MSN messenger. Neither firefox nor IE 6 / 7 allow me to get into gmail. I have had this problem since installing IE 7. Also the RUN function does not work it says "the system file is not suitable for running MS DOS and Microsoft Windows applications"
Please Help,
Alberto

 

Wow, well what i would suggest is running scans for spyware and viruses also get rid of IE7 (download IE) if this still doesnt work then MAYBE a reformat job might have to do.