Hi. I have a Dell XPS1645 Studio which came with Windows 7 x 64 bit Professional installed some 3 years ago. Last year I built a new desktop PC for work purposes (research Human Mechanics/ Motion). (Samsung SSD 128G 830, IB i5-3750K CPU, GTX66oTi, 16G xDDR3 Ram, Asus Sabertooth 77 M/B, etc). The Dell has served me well and I would like to keep it, it has recently run out of it's 3 year warranty. I want to exchange the hard drive in both computers. I came up a little short in my estimates on the SSD for the PC build with only 128G (the OS, programs etc take up more than the 50% mark and I can't trim it down enough. The Dell has a standard drive which I would like to replace with a top end SSD. The 128G SSD from the PC would be OK for the Dell and I would replace the 128 SSD currently now in the desktop PC with a Samsung 840 250G as main drive, with existing 1TB Samsung HDD to remain as storage. I have a number of high end, 500G-1TB external drives I can hook to the laptop for storage. I have the retail pack Win 7 x 64bit Home premium disk for the PC. The Dell was OEM but the serial number is still on the Dell laptop. Both computers are in a Homegroup network and I also have an Apple iPad3 also linked. It would be nice if I could take the SSD from the PC and slot it into the Dell laptop and do a clean install in the Desktop with the Retail Pack I have on a new 250G SSD, but I guess there is no known way to do that? Where do I download Win 7 x 64bit Professional for clean re-install to the laptop? Thanks for any advice.