I have already read various thread but still don't have a clear idea about the best solution. It seems the best and safest way to go is to get an official ISO instead of already activated copies and then activate it manually. Is this right? Right now I have one disk with XP on the first partition, and Vista on the first partition of a different disk. If I turn on the PC and do nothing, XP boots. When I press F8 for the bios boot menu I can select the second disk and then Vista boots. What I'd like to do is to wipe Vista and replace it with windows 7, and keep the configuration exactly as it is without the risk of messing my XP install. My fear is that using a loader I mess the boot sector and XP won't start anymore, and I want this to be safe. I don't want to risk to have to reinstall XP. So what's the best procedure? I download the ISO, then install on the Vista partition without using any codes. This will likely overwrite the boot sector on the first disk, so next reboot I get into 7 but can't get anymore into XP. What should I do next to put XP on back as default and start working to activate 7? I'm also reading that if I use the loader some parts of 7 won't work like the XP emulation, is this true?