Friend brought in a OEM-looking package of Windows 10 Home x64, part # KW9-00129. Everything I have seen on searches indicates it is a PL/Polish version, unless my search-FU is sucking it today LOL. Did a US-en install from my normal USB thumb drive, key won't activate, says it's for a different version of Windows. Are there any websites out there with lists of what the different part #'s for Windows 10 are? I'm pretty sure I'm going to have to tell him he got boned by a eBay seller and needs to get a hold of them. ----- EDIT (Update): According to friend, he ordered this from fleaBay and according to bid he was ordering KW9-00140m which matches the part # on Newegg and I am guessing what he should have gotten. Sounds like the seller FUBAR'd and sent wrong package. Just going to tell him to contact seller.