Ok. Please do the following & we will see if we can get it sorted for you.
Download CWShredder from here & run it. Select the fix button & it will get rid of everything related to CoolWebSearch. Close ALL other programs & windows, including IE, before running CWShredder.

Download & instal Adaware from here
& update it B4 scanning.
In settings under 'scanning,' have it set to
'scan within archives,'
'scan active processes,'
'scan registry,'
'deepscan registry'
'scan my IE Favourites for banned URL's,'
'scan my host's file.'
Also in tweaks under 'cleaning engine' set it to 'Automatically try to unregister objects prior to deletion.'
When the scan is finished select 'next.'
Remove what it finds by placing a check in the box to the left of the object. Reboot

Download & instal Spybot S&D from here Update it B4 scanning. Go into settings & have it check for Beta releases also & download if available.
After the scan is complete, have spybot fix everything marked RED.
On the page that first opens when you start Spybot there is an option to immunise, you should do this. In the immunise section there is also a link to download Spywareblaster. Download that & you can keep it updated by selecting the same link that you use to download it. Reboot

If you still have problems Download HijackThis from here & unzip it into it's own, permanent folder, not a temporary one. Start HJT & press the scan button. When the scan is finished the scan button will change to save. Save the log to a text file & paste it into the body of your post. DO NOT FIX ANYTHING YET.