Microsoft has changed their long term tradition of upgrading from a previeous version  of windows with the release of Vista. This time its not going to be easy upgrading. Last time around when performing a clean install of Windows Xp Professional using a upgrade CD, users would run through the normal setup routine until prompted to insert a previous version of Windows. A user to pop in a Windows 98 or a 2000 CD for upgrading and then the setup will run in its normal routine.

 This time thou Microsoft has done a different thing(practically annoying) now users are who buys an upgrade CD will have to have a valid install of have a valid install of Windows XP Home or Professional on their machines before upgrading. For most of all who have a genuine install of Xp or Home this wouldn't be a problem. But for do-it-yourselfers who buy a Vista upgrade CD, and inbetween the installation gets stuck, well the real nightmares starts then. Because if you get stuck inbetween the installation process and have no option but to perform a clean installation with Vista Upgrade CDs then you will have to:

1) Install a genuine copy of Windows XP Home/Professional
2) Activate Windows XP through Microsoft
3) Upgrade to Windows Vista from within Windows XP

 So for those who are planning to party by buying Vista upgrade CD's beware, if setup goes mad in the middle, your nightmares will start then. But for those who can dish out some more for a full copy of Vista you are good to go at anytime.