Had a similar problem last year on my wife's Vista laptop after she downloaded some Facebook app... It got past the (fully updated) AVG antivirus system and infested the system just like described here, so bad that even Safe mode would not execute the virus scan or allow reloading a Restore Point. I eventually found Avira AntiVir (http://www.avira.com/en/support-download-avira-antivir-rescue-system), and the bootable linux system was able to scan and clean the system. After booting back into Vista, I was able to run AVG and MSE, which both found additional problems on secondary filesystems which I did not clean with Avira. After several scans, I was finally satisfied that all problems were found and removed. Avira AntiVir is now part of my toolbox!