Yesterday I suspect I got infected by a virus.
Windows 7 x64 and NIS 22.5.2.15.
Any call to a programme results in a call to Windows Media Center, and all icons turned to WMC icon.
This problem is known and well described (search for “Window media virus”).
I founded an easy, although risky, in http://www.sevenforums.com/system-security/313083-help-getting-rid-windows-7-media-center-virus.html#post3150732
NIS did not stop this virus, if it is a virus.