Download CWShredder for use later in safe mode.

CWShredder is a specialized spyware scanning application which scans for and removes variants of CoolWebSearch, historically one of the most obnoxious and difficult to remove examples of verminware. It can be download free of charge from InterMute, now a part of Trend Micro. Run it anytime another scanning program detects anything related to CoolWebSearch to make sure all traces of the malware have been eliminated.

This procedure is intended for use in normal mode or safe mode with networking to prepare for a scan in safe mode.

Browse to http://us.trendmicro.com/us/products/personal/CWShredder/ and click Remove CoolWebSearch.
In the File Download message box select Save, and in the Save As dialog select to save cwshredder.exe in Desktop.

Scan with CWShredder whenever you have reason to believe that there is a variant of CWShredder on your computer.