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Possible Duplicate:
Can I transfer a Windows 7 license to another computer?

Often I have friends come to me wanting me to fix there PCs. Usually it just means they have a tangle or virus and junk and I prefer to just wipe the drive and start over. This seems like the best solution?

My problem, if I do this, is how can I put a valid Windows version back on their PC without buying a copy all the time? Is there a better way to do all this?

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marked as duplicate by random Feb 9 '12 at 3:21

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Take a look at this please: – climenole Feb 9 '12 at 2:40
the copies on the disks are all the same, it is the licence that matters, if they do not have a licence , that should be the only real problem. I often use the same disk, but the correct Key thing for that computer. If they dont have licence, and key and legit activations and all, it is probably why they are getting the rest of thier crack software Full of viruses :-) 2 ways to pay for software, buy it or donate your computer to possible cracker :-) – Psycogeek Feb 9 '12 at 2:40
@Psycogeek, who said anything about cracks? Don’t jump to conclusions. Maybe they are just sloppy in their Internet activities and need some security education. – Synetech Feb 9 '12 at 3:20
Does not seem to be a duplicate but deals with installing on the same system – Dave M Feb 9 '12 at 3:23
Interesting how this question was closed for being an “exact duplicate” of Can I transfer a Windows 7 licence to another computer?, but that question is closed for being an “exact duplicate” of When reinstalling Windows 7, does the language, version, architecture (64-bit or 32-bit) or source (OEM, retail, or MSDN) matter?. Yet, this question does not link directly to the second one. Funny how A=B and B=C, but A≠C. Math has no place in SE! :-p – Synetech Feb 9 '12 at 3:44
up vote 2 down vote accepted

If they have the original Windows CD, you can just use that with their previous license key. If they don't, you have to try trial and error to work out which CD matches their license key. For Windows XP in particular, you need a CD with the correct edition and service pack. Combinations can be made up of:

XP / Vista / 7
Home / Professional / Business / Ultimate
Original Release / Service Pack 1 / Service Pack 2 / Service Pack 3

I have this problem at work all of the time, where I have the license key, but don't know which version of Windows was originally installed. I had to trial-and-error three different installations before I found the correct one.

So if you can burn a copy of each Windows CD, you can be sure you can reinstall with an existing key.

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Use the license key from the version that is installed on the problem syste. It will be on the label on the system. If you do this often, you may need to call Microsoft to activate. However, this is very simple.

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If its a XP system, the key on the sticker on the system would work with media of the same sort (- that is to say, you can use the key on an OEM box with a OEM install cd - so a 'generic' OEM XP home disk can work with the key the sticker on a dell box (for example) and likewise. You wouldn't need fresh media, just one copy and the licence that came with the system.

With windows 7, the files for all versions are there so you can, with a little work build a universal installer for them.

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