As far as updating to XPSP3 goes... it will run the Windows Genuine Advantage software which runs before most of the newer software. I think you will be able to install it but you will suffer with a pop up that your copy of windows is not Genuine there after. I wouldn't condem this if you know if you have a non Genuine Windows install its better to look at upgrading to a Genuine version down the line if you can. If the purchase becomes an issue at all you could install Ubuntu which is free this way you can use it for flashing but boot into windows current windows install when you like. Install Ubuntu as a secondary OS so you have the option to choose which one you want to use after the Post boot phase of your pc. www.ubuntu.com/ You might even find you like Ubuntu and ending up ditching windows for it.