I am infected by System Check. This is the first malware I've gotten since I installed Windows 7 x64 over 26 months ago! It came in while someone was using the Guest account (Standard User). When I came home and discovered the infection, I logged off the guest account, logged into another standard user account and attempted to update MSE. MSE refused to update, citing a possible system or registry error (paraphrased). I promptly shut the system down, and will leave it shut down until I have a plan of attack. MSE is the only security software currently installed. It was last updated about 05:00 on 2012/01/04. I can readily pull the hard drive and scan it from another system, if there is an effective procedure for removing the malware in this manner.