Windows Vista upgrade hangs at 62%

Reboot, and your PC should roll back to Windows Vista. You can then open the setup log file \$WINDOWS. BT\Sources\Panther\setupact.log to view what happened. Microsoft say this is usually caused because the Iphlpsvc service has stopped responding, and just adding an environment variable to ignore it will fix the problem. Point your browser at http://support.microsoft.com/default.aspx/kb/975253 for the fix.