Scanning your computer for virus / malware etc using a bootable live Antivirus CD is most effective method. Using bootable antivirus CD you can boot your computer and scan complete system without booting into operating system.
What is bootable Antivirus:
Bootable Antivirus are like Live Linux CD with inbuilt antivirus. It contains basic linux system files. No installation is required to run bootable antivirus. Its based on Linux OS, but it also remove Windows virus.
How to use Bootable Antivirus
Below is list of three Best free Bootable Antivirus.