Ok, this is a problem that's been going for more than a month now. It's driving me nuts and I will prostrate myself in front of this forum and pledge my undying allegiance if you can fix it. Or help in any way. The build (the relevant parts at least) Core i5 2500K 4GB G.Skill Ripjaws-X 1600mhz Gigabyte Z68X-UD3P-B3 Inno3D GTX 580 OCZ Vertex 3 120GB SSD 3x HDD 550w PSU DVD RW optical drive Windows 7 Professional 64bit OEM Brief background Had old computer using this copy of Windows. Bought new parts, assembled new computer. Installed Windows. Problems - When at the part of the install that asks for a CD key, I punch in my key. It rejects it anywhere between 3-5 times, then just accepts it. - Various Windows services keep crashing. The Software Platform Protection Service (sppsvc) and Windows Media Player Network Sharing Service (wmpnetwk or something) in particular. Also Windows Defender from time to time. Also when installing via Windows Update, the Windows Malicious Software Removal Tool also crashes. - If I skip entering the CD key during install, and try and do it in Windows, it does one of several things. It will... + Activate online. Then a few minutes later 'de-activate' - that is, in System Properties the Status and Product ID are "not available". + Refuse to activate online, phone activation will either do the same as above and deactivate shortly after activation, or it just won't accept the numbers I put in. Says they're incorrect. And yes, I triple checked them. + The Activation Client won't run. It will crash when trying to start. Gives a message that the 'RPC server is unavailable'. These three things above happen seemingly at random. It's always one or the other. - I will periodically get the watermark in the bottom right of the screen saying "Build 7601 this copy of Windows is not genuine" - For some reason, I'm having a lot of trouble browsing the internet. Several different iterations of Firefox (different releases, as well as CometBird and Waterfox) all crash anywhere between 30secs - 10mins into a session. I can sometimes force it to crash by accessing Facebook or Youtube, but again, sometimes it works fine. Opera has crashed once or twice, and Google Chrome keeps giving me those 'Aw snap' messages. I think that's all. Now, the attempted solutions... - Have reinstalled. About a gagillion times. - Tried installing off flash drive, tried using the DVD drive. - Tried using three different Win7 install discs. One of which was a SP1 updated install. - Have installed on different hard drives. - RAM is fine, and according to a PC shop the mobo is fine. - Reseated and checked cabling till my hands were raw and bloodied. - Installed Vista Home Premium 32bit full retail version. Vista's equivalent of the sppsvc (called something different but similar) also crashed repeatedly. - SSD firmware is up to date. - Tried several different BIOS versions. - Ran IntelBurn Test and CPU appears fine. - Checked the CPU socket for damaged pads. - Tried several different LAN drivers - Brought it back to barebones - mobo, 1 stick RAM, CPU, gfx, SSD. Same problem. - Enabled AHCI in BIOS. - Took the box to where I bought the mobo, asked them to fix it. The guy said he'd never seen anything like this before. Managed to stop the popups for sppsvc and wmpntwk telling me it had crashed. But in Event Viewer sppsvc is still crashing a couple of times until it just gives up. He did that by installing Comodo Internet Security, so basically he did nothing. Because if I wanted to stop the popups I'd just stop the services ever starting. Fed me some bs about my CPU hardware ID being blacklisted and to call Microsoft. Games and stuff run fine, no other instability at all. Due to my post count lacking, I can't post the original thread over on Atomic, but they've helped me thus far and suggested I come here to see about messing around with Windows 7. If anyone wants a look at the thread I can PM them the link. I understand an OEM version is locked to the original board it's installed with, but would that cause system instability? Wouldn't Windows just be all 'You're a pirate. Arr.' Only once was I presented with that screen within the Activation Client that asks me if I'm installing on a new computer yadda yadda, it crashed shortly after and I haven't been able to get it back. Pretty much covers it. So, does anyone have any ideas what is causing these problems? And, can anyone help me fix it? I don't mind reinstalling, formatting yadda yadda, I'd like to avoid messing with the BIOS but I will if I have to. In the end all I want is a nice stable OS which doesn't keep throwing random errors on screen or telling me that my copy isn't genuine. Thankyou in advance for any and all help.