Hi, i've read the tutorials on changing the cversion to = 7100.0, and changing your registry of your rc ultimate copy to show edition as "Enterprise" instead of ultimate. However, here's the problem..it's still not letting me upgrade, and i'm not getting the same error as everybody else when trying to upgrade from RC (maybe because i got my copy of w7 through my school?) Instead of it saying i'm upgrading from a prerelease, it says this: Windows 7 Ultimate cannot be upgraded to Windows 7 Professional. You can choose to install a new copy of Windows 7 Professional instead, but this is different from an upgrade, and does not keep your files, settings, and programs. YouÃ¢â‚¬â„¢ll need to reinstall any programs using the original installation discs or files. To save your files before installing Windows, back them up to an external location such as a CD, DVD, or external hard drive. To install a new copy of Windows 7 Professional, click the Back button in the upper left-hand corner, and select Ã¢â‚¬Å“Custom (advanced)Ã¢â‚¬Â. Again, I've already changed the cversion and changed the registry of my RC to show as "Enterprise" in the editionId instead of "Ultimate" How else can I upgrade? This is rediculous..