Upgraded Serial Number

Hello. I upgraded into windows 7 from one of my computers at home. I need to know which serial number I upgraded from because I [EDIT: NEED TO] reformat and now I need to go through the process of installing the old operating system, then doing a clean install of win7 while the old operating system is installed and registered. So is there any registry trick or stored file somewhere that I can retrieve which of my old windows numbers I upgraded from?

Rant: This process is somewhat frustrating

What kind of win7 install disk do you have? Is it retail or upgrade?

If by upgrade you mean, is it upgrade only, then yeah, it is upgrade only which is why I have to install my old operating system before I re-upgrade. If by retail you mean did I get it from walmart, then its retail.

Oops I made a mistake in my original post. I still have my windows 7 install but it is not yet reformatted, so from it I would like to retrieve the key I used to upgrade it. I know which windows 7 key I used, but not the one from before that.

cabledevin said:

If by upgrade you mean, is it upgrade only, then yeah, it is upgrade only which is why I have to install my old operating system before I re-upgrade.

No you dont have to. See here how to.

Clean Install with a Upgrade Windows 7 Version

But this is legal only if you own a previous qualifying OS (need not be installed). So if you have one, you're fine.

Thanks for your help, but that isn't entirely the problem. I can install windows 7.

When I try to activate I get this error:
0xC004F061

Ignore what I wrote above. That website tells me how to fix that problem too. Thank you very much I appreciate your time and effort.:)

cabledevin said:

Thanks for your help, but that isn't entirely the problem. I can install windows 7.

When I try to activate I get this error:
0xC004F061

Ignore what I wrote above. That website tells me how to fix that problem too. Thank you very much I appreciate your time and effort.:)

worth to have a look at this one

Windows 7 activation error: 0xC004F061