Can you use the upgrade DVD of window vista home premium to perform a clean installed on a PC that already has window xp professional installed?

Answer 1

Technically no.

However, assuming you have a valid XP license, it's really a technological / user preference issue whether you bother keeping the old XP files on the drive or not; it's frankly none of Microsoft's business whether you erase them or not, or when you choose to do so.

So, assuming your XP license is valid, just do this:

1. Install Vista. Don't enter a license key, and don't choose to do an Upgrade install, do a Custom install. At the step of the install where you select a hard drive partition to use, go ahead and format it, just as if you were doing a full clean installation.

2. When you're asked to activate Windows, don't. Your upgrade install keys won't work anyway.

3. At this stage, your computer will have a clean install of Vista. The only problem is that it will stop working after 30 days.

4. However ... you now have a computer with a clean install of Vista, and you can use the upgrade keys to upgrade from a version of Vista to a version of Vista, even if the two versions of Vista are actually the same. So install again and choose to do an upgrade. You'll overwrite your clean installation with an upgrade installation, but they'll be the same files that came off the disk the first time. The end result is that you wind up with an "upgrade" copy of Vista that's essentially identical to that you'd get from a true clean install, and since it's an upgrade and you did an upgrade installation, your upgrade keys will work.

The above procedure is probably sufficient if you're fairly computer savvy, but if you need your hand held, search for "vista clean install from upgrade media" and you should find sites with more details.