Vista takes forever to load on bootup, when it does load

I just had a friend put together a new computer for salvaging some old parts and mostly new parts. I have an antec 900 case, evga e8400 mother board, nvidia geforce 8800 gt graphics card, and two wd 600gb HDD with 4 gb ram.

I installed windows vista on one of the discs, and it started out rebooting fine, however it seems to take literally minutes to get to the vista sign in. I have a blinking cursor for minutes, than sometimes it will wake up and fully load and show the sign in. Other times it seems to just hang sometimes with blinking cursor, sometimes without.

Does anyone know what could be causing this and what I can or should do about it? other than uninstalling vista and going back to xp? vista does load quickly after signin, but the wait from hitting power button to actual sign takes forever. Thanks in advance.