I think if I was you I would first download and create a boot CD of Microsoft scan alone sweeper and run it.
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.
Microsoft Standalone System Sweeper Beta is not a replacement for a full antivirus solution providing ongoing protection; it is meant to be used in situations where you cannot start your PC due to a virus or other malware infection. For no-cost, real-time protection that helps guard your home or small business PCs against viruses, spyware, and other malicious software, download Microsoft Security Essentials*.
To get started, please make sure that you have a blank CD, DVD, or USB drive with at least 250 MB of space. Next, download and run the tool – the tool will help you to create the bootable media required to run the software on your PC.
Should I download the 32-bit or 64-bit version?
1.Whether you download the 32-bit or the 64-bit version of the Microsoft Standalone System Sweeper Beta depends on the architecture (32-bit or 64-bit) of the Windows operating system of the computer infected with a virus or malware. See the Microsoft Help and Support article for instructions on how to determine whether a computer is running a 32-bit version or 64-bit architecture of the Windows operating system.
2.Ordinarily, the bootable media is created on a computer that is not infected. The architecture of Microsoft Standalone System Sweeper Beta does not have to be the same as the Windows operating system of the computer used to create the bootable media. It does need to be the same architecture (32-bit or the 64-bit) as the Windows operating system of the computer infected with a virus or malware.
* Your PC must run genuine Windows to install Microsoft Security Essentials. Learn more about genuine Windows. Internet access fees may apply.
Read the Microsoft Standalone System Sweeper Beta Privacy Statement and License Agreement.