Right, to stop people asking the same questions over and over again in loads of different threads, READ the thread first, if you have a question or need clarfication post and it'll be answered ASAP. Please lets not clog up the Windows forum with endless threads. When the thread is finished, the answered will be added to the sticky. Thanks Burnsy Please note: FAQ: No, because if you change the MB in the machine you revoke the OEM licence and therefore you don't have the right to use the upgrade without a qualifying product. You can install Vista with an upgrade disc without needed a current install of XP, you will need an OEM or retail disc and possibly the product key. You can upgrade your system if you have an OEM licence, however, the OEM licence is linked to the machine it was sold with. So, with all the upgrades you may wish to carry out, when is your PC no longer the original PC and when is it a totally new machine? Well to simplify things, Microsoft has defined the term ‘device’ to have changed when the motherboard has been replaced, therefore any motherboard upgrade would be deemed a new machine, which would require a new licence. In the past, Microsoft has been quite lenient in their policy of giving out activation codes. With Vista, Microsoft has made a firm stance about not giving out activation codes to people who have violated the EULA. So in future you may be denied activation which would render the product useless. Retail bypasses this problem as the licence is not tied to the machine it was installed on, and consequently you can change the motherboard and still have a fully licensed machine.