If you’re planning to upgrade to Windows 7, you better hope you have a high end machine with not very much data.

According to Ars Technica, Microsoft tested Windows Vista upgrades to Windows 7 on various machines, configurations and amounts of data, and while some systems were able to do it in as little as 30-minutes, the longest took 1220-minutes, or 21 hours.

We here at StarterTech have never been big fans of major operating system upgrades like this one will be.  As I am fond of saying, “Have you ever tried changing a table cloth without taking the dishes off?  That’s exactly what changing your OS is like.”  While it can be done, it doesn’t always mean that it should be, and if you aren’t really computer savvy, I would definitely not recommend trying it.

There are also questions of hardware compatibility, software compatibility, driver compatibility and on and on.  If you want Windows 7, we recommend you just wait until the next time you buy a new system and get it as a fresh installation.

Below is the chart that Ars Technica provided showing what you can expect in the ways of upgrade times from Windows Vista to Windows 7.  (Remember, Windows XP to Windows 7 is not recommended)