Well I have tried windows 7 on multiple pc's and with multiple pools with various psu's.
My asrock z77 itx-e motherboard:
http://www.asrock.com/mb/Intel/Z77E-ITX/index.us.asp with an intel i7 3770t cpu
http://ark.intel.com/products/65525/Intel-Core-i7-3770T-Processor-(8M-Cache-up-to-3_70-GHz)
a crucial msata for the hdd
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148698&nm_mc=OTC-Shopping&cm_mmc=OTC-ShoppingNet-_-Hard+Drives-_-Crucial-_-N82E16820148698&scpid=8&scid=scsho5457688samsung ram 2 4gb sticks.
and an antec psu
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371056runs 30 five chip units under at 300 watts nonstop for days on end. clocked to 850 freq. I get about 10200khs or 340khs a unit.
A lot of stops are your pools getting hosed by ddos attacked. I use wemineltc.com and cex.io to mine I only mine ltc for the sale of keeping things simple.
I never use anything but the custom cpuminer set at freq 850 for scrypt only.
I use less power for 10,200 khs then 1 r 290x does for 800khs
biggest problem is wire management. not stability…. but 4 other mobos running windows 7 or windows 8 suck compared to the asrock.