Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have two Dell PCs. And each PC has a Windows Vista disc and a Windows 7 upgrade disc which Dell gave me for free. And each disc has a product key. There are 4 product keys in total.

I'm going to sell one of the Dell PCs. But unfortunately I don't know which product key of Windows 7 corresponds to which product key of Windows Vista. If I sell the PC with wrong combination of a Windows Vista and a Windows 7, error will occur and I will get in trouble.

How can I know which Windows 7 corresponds to which Windows Vista?

share|improve this question

migrated from Jun 24 '11 at 5:47

This question came from our site for professional and enthusiast programmers.

are the windows 7 updates installed? – Journeyman Geek Jun 24 '11 at 7:24
7 of both machines are clean installed. – js_ Jun 24 '11 at 8:11
up vote 1 down vote accepted

I suspect which Windows 7 upgrade disk you use is irrelevant. The only thing that should matter is that the Windows Vista version matches the license key version. For instance, if you have Windows Vista Home for one PC, and Windows Vista Starter for the other, then the license keys won't work for each other.

Check the COA/license key on the back/bottom/side of each computer, and make sure it matches. If you can't tell, then I suggest trying to install Windows Vista (and then upgrading to Windows 7) before you sell the computer. If it doesn't work, you've got the wrong disk, so try again.

You are, of course, planning to re-format the drive before selling your computer, like any responsible computer user would, right?

share|improve this answer
i hope which disc i use is irrelevant as you say. but i asked dell. they said it is possible that error occurs if you use the product key which doesn't corresponds to vista. and they also said it is possible that activating 7 with the product key can maybe succeed at first but 30 days later error will occur if you use a wrong product key. is dell customer support right? – js_ Jun 24 '11 at 8:08
You'll have to use a Vista product key with Vista, and a Windows 7 product key with Windows 7. You also have to use a Vista Home product key with Vista Home, etc, as I said earlier. Beyond that, I don't think it matters. But I can't swear to it. – Flimzy Jun 24 '11 at 8:12
thank you very much for your answer and comment. i think you are right, too. but its risky to sell it if dell is right. im gonna ask dell again. and if i cant get the answer, i will ask microsoft. – js_ Jun 24 '11 at 8:20
@js_ Flimzy is 100% right in his second comment. You can do that with no regrets...just make sure you match the version as he said, home to home, etc. – KCotreau Jun 24 '11 at 11:57
thank you all ! yesterday, dell answered that the correspondence relation between vista and 7 is made when i upgrade to 7 from vista. and after upgrading to 7 from vista, a error occurs if i use the product key of 7 or vista (which i used for the upgrading) for the other pc. – js_ Jun 25 '11 at 16:40

You can check the current key for the system with magical jellybean keyfinder. There is no way to work out what the key is for a specific system though - but you can tell which SKU a key is for since usually the COA or packaging the key is on should say what version the key is for.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .