You might have heard about HiJack This software. If no, then here is a brief introduction about it.
HiJack This is a free tool that checks the contents of key areas of the Registry and hard drive--areas that are used by both legitimate programmers and hijackers and gives a log file to you.
Now this log file is given to some advanced users who analyzes it then you can manually remove all the illegal programs from your PC. Here is a free service that analyze your log file for free and gives you the result within no time. Below are some steps on how to use this service.
a) First download Trend Micro HijackThis 2.0.2 from here
b) Now run a deep scan and copy the log.
c) Now visit HiJackThis Log File Analyzer and paste your log there and click on Analyze. Have a look :
When you will click on Analyze, you will be redirected to a new window and list of running processes will be given. Bad or potentially dangerous processes will be flagged red.
Just copy the name of the dangerous process, search in it your computer and delete it permanently from your hard disk. In this way you can manually delete all the viruses and spywares from your PC.