A Microsoft support forum’s been inundated with complaints from folks trying to upgrade to Win 7. The problem being reported:

“When attempting to upgrade from Windows Vista to Windows 7 the upgrade attempt may fail with the message ‘This version of Windows could not be installed, Your previous version of Windows has been restored, and you can continue to use it.’ However, the next reboot of the machine will launch the upgrade process again only to fail with the same message.”

The problems users were reporting didn’t seem to be confined to one particular scenario — other than trying to upgrade from Vista to Windows 7.

Some folks having the problem had purchased a Windows 7 upgrade electronically from Microsoft’s online store, while others downloaded the upgrade from Digital River, the Minneapolis-based company that distributes Microsoft’s $29.99 upgrade offer to college students.

Still others suffering the problem bought their copy of the new operating system at a retail store.

A similar problem affected Vista users back in February, 2008, when they were prepping their systems to install the Vista Service Pack 1 (SP1). XP users were also afflicted a few months later when they tried to install an upgrade to SP3.

The difficulty bodes ill for the much-anticipated Windows 7, which was enjoying a somewhat positive reception, primarily because it wasn’t Vista. This glitch may prompt flashbacks for many Microsoft users contemplating an upgrade and wary of past incidents.

To read about the problems, visit the Microsoft support forum here.