You could try a ps2 keyboard or check your bios to see if it can be set to recognize a usb key board on boot. DavidR has posted about this and says he keeps a regular keyboard on hand as sometimes the keyboard will not work even though the bios is set.
Okay, you appear to have your previous av removed.
There seems to be some conflict between spyware blaster and spybot see here
http://forum.avast.com/index.php?topic=23407.0
Did a standard scan ever work?
Did you try a repair?
Control panel, add/remove programs
click on avast, click add/remove button
you should be given the option to repair, you have to be on line to do this.
You could also uninstall/reinstall. Use the uninstall tool
http://avast.com/eng/avast-uninstall-utility.html
reboot before reinstalling
oh yeah, welcome to the forum