windows xp pro - lost and overwritten product key

I had a licended version windows xp pro installed. I couldn't boot the computer anymore and repair hasn't been successfull. A friend installed his windows xp home version which changed the registry and I cannot
find the product key for my windows xp cd.
I found a registry backup file from last year and thought it might contain the product key for xp pro but cannot access any data. How I can access this backup or is there any other way to retrieve the product key for installation ?

Thanks for your help,
Birgit

 

my guess, if you registered, contact MS and they should have you in their database...take it from there...

 

Thanks - I shall ring MS - thought only I could find it myself as I saw so many hints about retrieving product keys.

 

Those programs only access the current key. What the code to find the key is a mystery. I'd love to find an opensouce keyfinder program so I can do what you are talking about, by reading the code.

 

What about the registry backup file - is there any way to access it or why has it been created at all ? I also would like to have access to other lost data and hoped there are information stored I could use.

Thanks,
Birgit

 

What other information was lost?

If you were to go to "documents and settings" directory, you should be able to find your old settings.....

I have a few unstable ideas that will more than likely not work....with your registry backup....

But, i'd search around your house for that cd key....

 

I would like to get access to my old emails and don't know how. About the key I shall ring MS or search further ;-)))))

 

What email program were you using?

 

Outlook express - found the addressbook but nothing else.

 

Just an FYI: Lost product keys cost 10 dollars from MS