AuroraHD :
I've said this several times but, I've heard you can ask Microsoft for a new key, is this true?
Very different circumstances. You could do this if you had bought an OEM copy of windows 7 and activated it on your PC. It would create a hardware ID associated with that key. Now if you ever upgraded, or say, needed a new motherboard, you could then call microsoft and see if you could get a new key for the OEM Windows 7 disc you bought so that you could put it on your new computer. It may also be that they assign the key to a new Hardware ID, and not give you a new key, I'm not entirely sure (I haven't done it myself).
Either way, there's no way to do it with a computer that you bought from like HP or Lenovo or Dell (et cetera).
As for the BIOS flash, there's no need to do one for the GPU's sake. You may need to do one if you're installing a Vishera CPU though.
The reason why this motherboard (and any motherboard with a PCI-e slot) is compatible with today's GPUs, is that all PCI-E slots are compatible forwards or backwards. I have never seen an instance where a PCI-e card wouldn't work with a PCI-e motherboard. (Most every GPU and Motherboard fall into this category. Especially a board you would buy)