What files does the Windows 7 upgrade disc look for? [closed]

I have a valid copy of Windows XP and a purchased a Windows 7 upgrade disc.

I like to wipe my drive clean when reinstalling my OS. However, the upgrade disc fails to install if it doesn't find a valid copy of XP on the disc.

Rather than going through the trouble of installing XP and then installing 7, is there a way I can "spoof" an XP install by placing some key files and the upgrade disc looks for on the hard drive?

Solution 1:

Here are the instructions for a hack that claims it allows you to perform a Windows 7 install via an upgrade license on a formatted or blanked drive.

1. Boot up the PC with the Windows 7 Upgrade DVD disc media into DVD-ROM drive.
2. Follow the Windows 7 Install Wizard to install the operating system
   • During installation, when prompted for a product key, DO NOT enter a Product Key
3. Unselect the check box for Automatically activate Windows when I’m online during the installation
4. Boot up to the desktop after Windows 7 finish installing
5. Activating Windows by one of the following options:
   • Manually enter the Windows 7 Upgrade Product Key to activate online
   • Activate via phone.

Note: The source of these steps are found here. If the above fails, there are three workarounds at the source's page. Two of three doesn't require reinstalling Windows 7.

Disclaimer: I haven't tested this. Use at your own risk.

Solution 2:

There's no need for hacks. As explained in another SuperUser question that actually asks about the goal and not the step ("Is it possible to remove all partitions when upgrading from Windows XP to Windows 7?"), the official Microsoft way to do this is to start the Windows 7 installer, and erase and re-create one's disc partitions from within the setup utility.