That's strange. I guess it's AV or "smart filter" complains. The RunAsDate's author warns that some AV solutions mark the EXE as a malware which it's not. They do that for only reason IMHO that the tool hooks Win32 API functions and is not on the whitelist and not signed. Anyway I've used it for years without a hitch, of course, YMMV.

I was able to stop latest pre-RedGate version 5.1.6.0 to update itself with a "dirty" hack circa 2009. :) "C:\Program Files (x86)\Nirsoft\RunAsDate\RunAsDate.exe" /movetime 11\08\2009 16:21:42 "C:\Program Files (x86)\RedGate\.NET Reflector\Reflector.exe" Just create a shortcut with command line like above and forget about updates. P.S. You willl need NirSoft's RunAsDate[^].