To Do List
C:\Documents and Settings\Your User Name\Cookies
C:\Documents and Settings\Your User Name\Local Settings\History
C:\Documents and Settings\Your User Name\Local Settings\Temp
C:\Documents and Settings\Your User Name\Local Settings\Temporary Internet Files
C:\Documents and Settings\Your User Name\Recent
C:\WINDOWS\Prefetch
C:\WINDOWS\Temp
C:\WINDOWS\Temp\Cookies
C:\WINDOWS\Temp\History\History.IE5
C:\WINDOWS\Temp\Temporary Internet Files\Content.IE5
Delete all files.
There are tools like ccleaner & Tune up utilities (free at download.com) which can delete all your evidences
Recommended Free (Available on Net)
Antivirus AVJ Free Edition (http://free.grisoft.com/doc/5390/us/frt/0?prd=aff)
Commodo - Firewall Pro, Anti - Malware, Antivirus, Verification Engine, Anti - Spam, Ivault & Backup
(http://www.comodo.com/products/free_products.html)
Spyware - Spyware Doctor (http://www.tucows.com/preview/365586)
Boost PC - Tune up Utilities or ccleaner (Removes junk Files)
Update Drivers - Driver Magician or Driver Genius
Update your Windows for Critical updates.