GPUs being ignored by Windows

Hi.

I have two nVidia 470m SLI with an Intel x58 motherboard chipset. Windows 7 Home Premium doesn't recognise my GPUs. (Both the 32 and 64-bit versions share this annoying problem.) Also, it ignores my ethernet and wireless adapter. These problems are solved when I install and use Ubuntu (based on Linux) instead. Then, both my graphic cards and wireless/ethernet work.

Why is this? I've tried everything on Windows, from editing the BIOS, to downloading and installing drivers, to installing third-party programs like Everest and Driver Sweeper. Nothing helped.

The only thing that helped was uninstalling Windows and using Linux instead. Since this is (supposed to be) a gaming computer, that's not a very helpful solution.

Any ideas? I'm about to install Windows again, just in case it somehow screwed up last time during installation. I doubt it'll work and I'm loathe to abandon Ubuntu when it's the only OS that's recognised my hardware, but I'm ready to try just about anything at this point.