|If you have a blank spare HDD, then you can clean-install Vista starting with the Upgrade Vista DVD.|
Or you can try at your own risk the following solution I found at:
This issue may occur if the UpperFilters registry entry has become
corrupted or is set to a blank value. Certain programs that may be
installed on the computer may have modified this registry entry.
This registry entry is located in the following location:
Value name: UpperFilters
Value type: REG_MULTI_SZ
Value data: PartMgr (default)
Warning Serious problems might occur if you modify the registry
incorrectly by using Registry Editor or by using another method. These
problems might require that you reinstall the operating system.
Microsoft cannot guarantee that these problems can be solved. Modify the
registry at your own risk.
To resolve this issue, restore the default value for the UpperFilters
registry entry, and then restart the computer. To do this, follow these
1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following registry subkey:
3. In the results pane, right-click UpperFilters, and then click
4. In the Value data box, type PartMgr, and then click OK.
5. Exit Registry Editor, and then restart the computer.
6. Insert the Windows Vista DVD, and then upgrade the computer to