The road to Windows 7 for Vista-shy customers who want to jump straight from XP to the upcoming operating system won’t be an easy one.

Microsoft confirmed yesterday that Windows XP fans would be able to purchase a licence and media to “upgrade” to the new OS once it lands.

But this being Redmond there is a caveat: XP customers have to perform a clean install of Windows 7. This means wiping their computer hard drive’s data first, which doesn’t sound much like an upgrade to us.

Unsurprisingly, the transition from Vista to Windows 7 will be much more straightforward because customers will get an “in-place upgrade” of the OS that should mean their data and programs will remain intact.

“I can confirm that customers will be able to purchase upgrade media and an upgrade license to move from Windows XP to Windows 7 - however, they will need to do a clean installation of Windows 7,” a Microsoft flack confirmed to The Register.

“This requires the user to back up their data, install Windows 7, re-install the programs and restore their data. For PCs running Windows Vista customers have the option of an in-place upgrade of Windows 7 keeping their data and programs intact or to perform a clean install of Windows 7.”

Microsoft is remaining quiet on how much lighter an XP customer’s wallet will be following the “upgrade”, but Windows plebs can presumably expect a cheaper price tag than if they simply walked into a store and bought the OS off the shelf.

The software giant revealed earlier this week that Windows 7 will come in six different flavours: Windows 7 Starter Edition, Home Basic, Premium, Professional, Enterprise, and Ultimate.

Many are predicting the OS will rock up at some point in 2009, but MS has declined to offer a date when it thinks Windows 7 will ship. ®