At the Infosec Security Conference, Mike Danseglio, a program manager in MS's Security Solutions group, admitted that Windows can get so corrupted by malware, that there is no recourse but to format and reinstall.

He even suggested that companies should invest in tools that will allow IT personnel to do this automatically. In one instance, he disclosed that an unnamed branch of the U.S. government had to manually reformat and reinstall Windows on 2,000 machines.

Yikes!!!