Takes long time to boot slow speed once booted



new build
asrock motherboard AMD quad core 8 gig ram
windows 7 ultimate
takes about 30 min to boot,
when it was ok taking only 2 min
now it requests system restore have to do a few times still not working
have to reinstall windows for it to work normal,
ok for few weeks then starts again being slow booting and not as good at managing tasks.