I really don't know why but this is what happens:
1. BIOS splash screen appears
2. Black screen
3. 3-5 minutes waiting ...
4. Desktop appears
I think it has something to do with the drivers. Im running both nvidia and AMD cards on the same rig.
That might be the difference there. I don't have any experience mixing AMD and NVIDIA together, but it seems plausible to me that it could take longer to boot up that way. Someone else running both NVIDIA and AMD on the same rig will have to verify or disprove that theory though...
*11 of our rigs are on 4GB RAM, the other is 8GB.
Why do you choose windows over Linux and what miner(s) are you using ?
We chose Windows because my wife is the one who deals with the machines the vast majority of the time and that was scary enough for her at first without bringing in a brand new OS on top of it. Windows keys are pretty cheap these days so the tiny extra cost is worth it for us.
have a rig with 4 amd and 1 nvidia. 120 gig m2 sata ssd, 8 gb ram, g1840 cpu, win7 pro. takes about 30 seconds from power on to claymore mining window to appear.