Since the release of Windows Vista, it was thought that the Upgrade Disc would install over your XP and invalidate the key. However, there had always been a workaround that just requires a few different clicks when installing with the disc.
So far, this workaround has been working for many. Microsoft even confirmed that the workaround was possible but warned that they would be violating the terms of use agreed to when they purchased Vista. There has yet to be a fix for Microsoft’s error.
The process is very simple, except you will have to install Vista twice. This process has worked for many, although I have never personally tested this.
1. Boot your computer using the Windows Vista Upgrade DVD:
To do this, make sure you have your DVD in your PC before your computer moves on to the 2nd screen at bootup. You may have to configure your BIOS so your DVD drive is recognized as a boot device.
2. Install normally but DO NOT enter your product key:
Make sure you follow this step. By not entering your product key, you will install Vista as a 30-day trial.
3. Select the version of Windows Vista purchased:
4. Re-install Vista within Vista:
Once you are finished installing Vista, go to My Computer, and install Windows Vista.
5. Install and type in your Product Key:
When prompted, enter your Product Key.
6. Perform a Custom (advanced) Install:
You will come to a point where you have to choose between an Upgrade and Custom Install. Make sure to choose Custom. Windows should now perform a clean install of Vista on your PC. Don’t forget to restart.
Although this may save you money, it is still cheaper to buy an OEM copy of Vista. You can read more about purchasing Windows Vista OEM here.
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