Windows 7: Using Windows 7 Key

Heres the background story: I own a Dell xps M1530 with a: 2.0 ghz dual core processor, 3gb of RAM, soon to be 8gb of RAM, and (currently) a 320gb 7200rpm hard drive. I purchased Windows 7 professorial 32bit as an upgrade from Windows Vista a few months ago with the student discount. Not shortly afterwards my hard drive started to go and 30% of the hard drive became unreadable. So I bought a new one(better one of coarse) I want to upgrade the RAM in my laptop to 8gb and I need a 64bit os to do so. I now am using Ubuntu 64bit on my laptop. I have legally got the installers for the 64bit version of Windows 7 professional and have succesfully installed it on my laptop. Here is my nexxt poblem: the code won't work. I tried using the same code I got from my vista to 7 upgrade. I have been told that I could use this same code because I installed the same operating system(7 proffesional) just at 64bit instead of 32bit. It says it cannot detect a previous version of Windows on my hard drive and thus it won't work. This reason is due to my replacing the hard drive since the old one didn't work. Does this mean I have to shell out another $300 for a full version of 7 professional? Or is there some way I could use the code I already paid for?

When you boot the Windows 7 DVD to install Upgrade Version it scans the HD to see any prior OS to allow use of Upgrade version key (even if you go on to delete, reparition or format).

You can install Upgrade version to an empty HD by not installing the Product Key upfront, then doing one of the workarounds in this tutorial after install: Clean Install with a Upgrade Windows 7 Version

You do not need to have the prior qualifying OS installed to use Upgrade version. Under the EULA you only need to have it on hand and not use it again once Windows 7 is installed.

A retail Upgrade can migrate to any computer of your choice for life, as long as it is on only one at a time.

Thanks, it worked!!!!!