I need to install xp 64 on my current system running xp 32 bit (I have verified that the system is indeed 64 bit, and have run diagnostics from Microsoft verifying the system is ready and compatible for 64 bit OS) QUESTION 1: Does installing XP64 require a clean re-installation of all my software (it is 64 bit compatible) ? (Win 7 64 requires this)** QUESTION 2: Is it possible, if the installation fails, to reinstall the 32 bit and the software? **REASON: All of my software is legal - the problem is it has been multiple upgrades over a period of years (ie: from Photoshop 5 to CS3), and in the case of CS3, it was purchased legally from a 3rd party vendor) This is the situation with most of my software, I would not be able to provide the original CD or installation .exe file, and the serial numbers would most likely not reflect the original installation I am not a gamer, I do high end graphics and illustration and use programs like Z Brush and others requiring large memory management capability - the more recent upgrades to these programs demand even larger memory use Thanks for your help, advice and suggestions. Nate