206546-microsoft-security-essentials_originalWe have recently started to see some systems come in where Microsoft Security Essentials is damaged by a virus infection to the point it cannot be reinstalled. Yes, MSE has gotten some bad press lately due to their performance in AV-TEST.org’s evaluations, though Microsoft has published some interesting data trying to map out the real world impact of what they missed.

But the troubling issue we are seeing is MSE being damaged beyond repair, even for what seem to be minor infections. You can’t uninstall it, and when you try to manually remove it, the reinstall will still fail with a variety of errors.