HELP trojan and worm found

Hello,
I have a viurs/malware on my other computer. I cannot do anything. I cannot open anything. A warning keeps coming up saying the application cannot be executed the file is infected. Please activate you anti virus software. The security monitor warning says it is trojanSPM/LX. It also says a worm Lsas.Blaster.Keyloger. A message came on the computer yesterday for me to update Internet Explorer version 8. I have had nothing but problems since then. Does anyone know how to get rid of this?