Please help me get some sense from Windows technical

I have a computer which came with Vista. I bought the Windows 7 Upgrade disk and when I did the installation it came up "invalid product key". After several false starts, transferrings to nowhere and people telling me the problem must be that I typed it wrong/used the caps lock key, I got through to tehnical support and they took me through about 5 steps taking under 10 minutes and which I now wish I had written down. (I didn't because I use third party imaging software and figured this was the only install I'd ever have to do. The third party software failed on me and I had to do a new install.) He told me this process had hard coded my computer to this product key and I would never have the problem ever again. Needless to say I have had the same error again trying to reinstall.

I called MS at about 16.00 and didn't get through the usual "have you typed it in wrong" or the extremely mindless "call us back when you find your product key" -> click until 17.50, when technical promptly told me it will take hours to fix and they refuse to do it till Monday, I am not allowed to use a clean install, I should pay for a passkey, they will help me on Monday with a one time passkey but this will not work ever again and if I ever want to reinstall again for any reason I will have to go through to technical support again!

He also tells me the usual gumph about you cannot use an upgrade disc unless you do an upgrade installation. Which requires you to log into a working system. If I had a working system I'd not be reinstalling at all!!!

Please, can someone help me with a way I can either

• fix the "product key not valid" problem myself, or
• tell me if there is a magic word to get through the various gatekeepers of the technical support department so I can speak directly to someone who can fix my problem, and what I should tell them my problem is in order to get someone who does the 10 minute fix without a lecture, not someone who gives me 40 minutes of holding on to be berated that I am making a mistake by not using an upgrade install and therefore it's my fault it doesn't work.

Would be ever so grateful!

Tearing my hair out here.

The link to the "clean install with an upgrade version of windows" tutorial, also contains a method to change a value in the registry which will allow to activate without the need to the upgrade install that greg mentioned. I used the registry hack method and it worked perfectly.

It's worth noting that if you bought Vista with a new computer, and then purchased the upgrade disc, support for the upgrade is supposed to come from the OEM, not Microsoft (it's in the fine print). Also, the previous posters are correct, and calling MS about it was likely to get you the company line that you must upgrade an existing OS (which you ended up doing :)). Anyway, really glad to see you got it sorted out.