Microsoft has made available for download an automatic fix designed to resolve failed upgrades from Windows Vista to Windows 7 in scenarios in which the process gets stuck at 64% indefinitely. With Windows 7 having hit the shelves on October 22nd, 2009, eligible users running Vista proceeded to upgrade to their recently acquired copies of Windows 7. And, while the general rule is that the jump from Vista to Windows 7 is nothing short of a smooth transition, some users found that the upgrade process stopped responding at 62%. In such cases, the operating system also creates a file labeled system_drive:\$WINDOWS.~BT\Sources\Panther\setupact.log. The specific log entries contained by this file are exemplified in KB975253.

“This problem occurs because the Iphlpsvc service stops responding during the upgrade. Other services may also cause a problem in which the upgrade process stops responding at 62%,” Microsoft explained. Microsoft does not have an update ready to resolve the issue. However, the software giant is by no means letting users hang out to dry. It has already offered a workaround that can be deployed manually, but, at the same time, it has also built an automatic fix that can be deployed effortlessly by Windows 7 customers affected by this specific issue.

“To fix this problem automatically, restart the computer where the upgrade to Windows 7 fails at 62%. Your computer will roll back to Windows Vista. Either download the [Automatic Fix] to a flash drive or to a CD or [the link] on the machine where the upgrade fails. (…) On the machine where you experience this problem, click the Fix this problem link. Click Run in the File Download dialog box, and follow the steps in the Fix it wizard,” Microsoft explained.

The Redmond company indicated that, although the wizard for the Vista to Windows 7 failed upgrades 62% automatic fix was in English, the workaround still applied to all versions of the operating system, independent of their locale. The company stressed that only users affected by this specific problem, namely Vista to Windows 7 upgrades that stopped responding at 62%, should apply the resolve made available. This workaround is not designed to address any other issues, such as the upgrade process being stuck at any other percentage than 62%.

For do-it-yourself cases, the workaround can also be implemented manually:

“To resolve this problem yourself, follow these steps:
- Restart the computer. Then, your computer will roll back to Windows Vista.
- Click Start, right-click Computer, and then click Properties.
- On the Advanced tab, click Environment Variables.
- Under System variables, click New.
- Type MIG_UPGRADE_IGNORE_PLUGINS in the Variable name field.
- Type IphlpsvcMigPlugin.dll in the Variable value field.
- Click OK three times to close the dialog boxes.
- Start the upgrade installation again.”

After the workaround has been implemented, either automatically or manually, users should no longer encounter any issues when upgrading from Vista to Windows 7.