Click Start / Run and type SERVICES.MSC
2) Look for the Virtual Disk Service
3) Right click it and choose "Properties"
4) Change the Startup Type to Manual, then click the Start button.
5) Reboot and try the upgrade again.
If there isn’t Virtual Disk Service listed, you can take the following steps to populate the disk information:
1) Click Start / Run and type devmgmt.msc
2) Expand the Disk drives and double click the disk.
3) Click Volumes on the disk Properties.
4) If the volumes information are blank, click Populate.
5) Insert the Windows 7 installation disc and launch Setup.exe
Best Regards