With todays malware, you're better off letting an expert decide on what programs and scanners to use based on what you're infected with.
As a general scanner.....you can't beat Malwarebytes Anti-Malware
You can download it from here:http://www.malwarebytes.org/mbam-download.php
The link below shows you how to run it:http://malwaretips.com/blogs/how-to-scan-with-malwarebytes-anti-malware-2-0/
Some tips on keeping your computer safe can be found here:
My Preventive Maintenance:http://maddoktor2.com/forums/index.php/topic,46886.0.html
Please let me know if you need more information.