I created a restore point earlier today on Windows 7 system. It reported that the restore point was successfully created. Later I ran Malwarebytes' scan which reported some threats, among them multiple counts of Siredef.C in C:\Windows\System32\SHELL32.DLL. When these were quarantined, the Start menu stopped working. (Or at least, I strongly suspect that must be the cause; no other system component was identified.)
Unfortunately, when I then went to Malwarebytes' Quarantine list, it was much shorter than the original list of threats, and SHELL32.DLL did not appear in that list at all, making it not available for restoring.
So of course I then reached for System Restore (by running rstrui.exe from cmd.exe). Unfortunately, it told me that there are no restore points! The named restore point I had created had vaporized.
How can I most easily recover this system?
P.S. prior to Malwarebytes, I had run Microsoft's sfc /scannow. It didn't report or repair any corruption, suggesting that the shell32.dll treatment was a false positive.
Running sfc /scannow now finds/fixes nothing.
