My security software is reporting a virus corrupting disk.sys. Their solution: remove the file. I restored an older copy of the file (though it appears to be the same size, etc.) to another location from a backup I had, and when I check it, it doesn't report any virus. But the existing copy, C:\Windows\System32\drivers\disk.sys, does.
1) Is this file required for proper operation of Windows 7?
2) If so, how can I repair the apparent problem?
(BTW, I took ownership of the file but I can't open it to run a compare on it; it says I need permission fromt he owner, even though I *am* now the owner. Nor can I copy the file to another location. I don't get that.)