I've run microsoft security essentials, malwarebyt's anti-malware and ccleaner in regular and safe mode and can't seem to pick up the virus/trojan that has disabled all my apps (MS office, firefox browser, MSE, etc.). I can get MSE to run (as administrator). When I launch any app, like microsoft word, I get a window that says "app not found".
I also tried reverting to an earlier restore point, but unfortunately they don't go far enough back prior to the issue.
How can I fix this?