Repair installation: error message about virtual machine

I am trying to to a repair installation on my Win7(64) Pro system: the one called "Upgrade" which does not delete user files, settings or programs. Every time I try to run the setup program from the DVD I burned from the Digital Rivers ISO I downloaded, the installation stops and I get the following Compatibility Report: "The following issues are preventing Windows from upgrading...Setup was unable to determine whether there is any virtual machine installed."

I've no idea what this means but want to fix the problem so I can run the repair installation setup. Any ideas?

This thread is the only time the specific error has been reported online. If Rich's suggestion doesn't nail it then check your BIOS to see if virtualization has been enabled and disable it to see if it quashes the issue.

Doing a clean boot not only didn't solve the problem, it created a new one: the Upgrade install program could not find any "information about the disks on this computer."

Regarding the BIOS setting: it was already set with virtualization disabled. Just to see what would happen, I enabled virtualization and did a clean boot to Windows. But that didn't affect the Upgrade reinstall: it still wouldn't run.

What is the problem requiring the Repair Install? They may be connected.

This is a very rare issue that may best be overcome by Clean Reinstalling to save time and get a baseline perfect reinstall (same steps for retail) which you can then image so you never have to reinstall again.

Set BIOS to defaults, wipe the HD first with Diskpart Clean Command.

The problem that started all of this is that suddenly & without any changes to any settings by me, Windows started prompting for permission to run programs that, previously, ran without user intervention. Furthermore, it did this everytime a program ran. When I tried to change my Administrative User Account Settings, Windows displayed a blank (e.g., all white) User Account Control Settings window which it then closed after seconds. As a result, I'm unable to change any User Account settings.

Check for infection with a full Malwarebytes scan. Replace any bloatware AV with Microsoft Security Essentials, run a full scan.

Work through these other Troubleshooting Steps for Windows 7 to gather clues, check for solutions.

Malwarebytes didn't find any viruses or other nasties and I stopped using bloated AV stuff (i.e., Norton, etc.) years ago,opting for Msft Security Essentials. And a System File Check ("sfc /scannow") failed to uncover any oddities with the system files. So, I'm organizing things for a clean reinstall. Whadda mess...