CRS

Crs32.dll, Crs.exe and crs.reg

Various shareware / spyware have been noted to install these files including:

Adsubtract

Adverting software from gratisware.com - be warned, when you get rid of crs32.dll and crs.exe ALL gratis software will stop working - see here: http://www.gratisware.com/Gratisware.nsf/htmlmedia/opt-out.html

Sundry games

You can try searching for and renaming the two files mentioned. Also search your registry for any references to the problem files and get rid of them as well (use MSCONFIG first to test and make sure you back up any registry keys before deleting).

NOTE: Crs.exe is also the name of a legitimate windows file associated with content replication on Site Server - it is the commandline tool.