Windows 7 Upgrade Could Take Over 20 Hours

While we're not going to dispute that a clean install is the way to run Windows 7, there are going to be many users who will choose the literal upgrade path from Windows Vista and perform an in-place upgrade.

The reasons to do an in-place upgrade are numerous. First of all, the core software changes to go from Vista to 7 aren't as drastic as previous generations of Windows. Secondly, the convenience afforded by the in-place upgrade allows users to retain nearly all software and settings without the need to restore any previously backed up data.

Another possible advantage to doing an in-place upgrade is time – it's supposed to be faster than starting fresh and reloading all your old programs. But in some cases, the upgrade could be the more time-consuming route.

Microsoft's Chris Hernandez of the Windows Deployment team detailed Windows 7 upgrade performance as compared to Vista SP1's upgrade behavior. Hernandez found that Windows 7's upgrade speed was faster than Windows Vista. Interestingly, the time it took for Windows 7 to upgrade from Windows Vista SP1 outpaced that of a Vista SP1 to Vista SP1 upgrade procedure.

At its very worst the upgrade from Windows Vista to 7 was found to take a whopping 20 hours. At that rate, a user would likely have less downtime if he or she just did a clean install and restored/reinstalled programs.

Most users will average upgrade times lasting just a few hours, but those with slower systems or exceptional amounts of data will have to set aside a good portion of the day just for the automated process. All clean install systems upgraded in around 40 minutes or less.

Marcus Yam
Marcus Yam served as Tom's Hardware News Director during 2008-2014. He entered tech media in the late 90s and fondly remembers the days when an overclocked Celeron 300A and Voodoo2 SLI comprised a gaming rig with the ultimate street cred.