Can't re-start computer after virus removal

Hello,
Got a virus that causes pop-ups for antivirus removal "program", and also some porn sites. Friend downloaded AdAware and used that, plus Symantec antivirus programs. Worked once, then husband went online again and we got it back. (I update the Symantec program every time I turn the computer on.)

Now, after running these programs, I can't reboot the computer to save the changes. Get the message "Program not responding, end now." If I don't click "cancel", I usually have to shut off the power strip to turn off the machine, it wont even turn off if I press the power button.

It seems to have affected my email program recently as well-- I can't open my messages in Hotmail once I log in. This only happens at home, not elsewhere. I reset the Internet Explorer to original settings-- no effect.

I had to restart automatic updates from microsoft, and I now see that the anti-virus shield icon is gone from the status bar at the bottom of the screen. HELP!!