as uber gerbil said, in bios there IS( depending on your mobo ) a setting, you can try the s3 or s4 power states. setting your computer to sleep in windows as opposed to hibernate is ideal. my guess is windows changed it's setting on you, i have this issue sometimes in win7 x64 ultimate. hope this helps.
mobo: msi 970 g46
gpu: ati 4850 @ 750core/1100mem arctic cooling twin frozr cooler
cpu: 955be @ 3.8ghz @ 1.375v's 2.6ghz n/b 1.275 scythe scrt-1000
ram: 2x2 samsung hyko @ 800mhz @ 6-8-8-24
psu: corsair 650hx
hdd's: 500gb + 1tb( 16 and 32mb cache )samsung