Here is a cool link I discovered that creates a bootable Microsoft disk which you boot from and can remove root kit malware which many times can not be detected by most security packages once it has infected a live system.
Here is a quote from the Microsoft web site:
"Thank you for contacting Microsoft Support. You have been directed here to download and install the beta version of Microsoft Standalone System Sweeper Beta, a recovery tool that can help you start an infected PC and perform an offline scan to help identify and remove rootkits and other advanced malware. In addition, Microsoft Standalone System Sweeper Beta can be used if you cannot install or start an antivirus solution on your PC, or if the installed solution can’t detect or remove malware on your PC."
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