An upgrade will work if you have a downlevel qualifying product - but Vista doesn't fall into this category.
OEM will work on a clean drive, yes.
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Browse All TopicsI am wanting to take Vista off my machine. Will an upgrade version work I can pick up at walmart or will I need an OEM version?
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Netmann made a good point that I forgot about. You can do a clean install with an upgrade CD, but you will get a message that says "Please insert a qualifying Microsoft Product" , at that point you will need to Insert A Windows 98, ME, or maybe even 95 disk in. I am pretty sure they would need to be retail copies, OEM disks will not "qualify".
If you have no "qualifying products" then you will need the full version
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by: superfooz74Posted on 2007-11-29 at 10:39:54ID: 20376037
You will need a full version, if it says "upgrade" it can only be used to upgrade older versions of windows, not to do a clean install of xp. To get a cheap full version of xp, try www.buycheapsoftware.com , dirt cheap.