Vista upgrade win7 system has unlimited restart solution

When users want to upgrade from Vista to Windows 7, the installer may prompt the following error:
 This version of Windows could not be installed, Your previous version of Windows has been restored, and you can continue to use it."
Workaround:
1, first put the Windows Vista installation CD, then open the Start menu, click & ldquo; All Programs - Accessories - Command prompt & rdquo; item, then choose to run the command prompt as an administrator;
2, in the open command prompt window, enter the following command and press Enter:
CD-ROM drive letter: ?ootBootsect.exe /NT60 All
3, then restart the system to solve this problem.