Error msg "Interactive logon process initialization has failed."

[sijui nini]

natumia window 7..nakutana na hiyo error pindi tu pc inapowaka kabla hata ya kulogin..after that huwezi fanya chochote..inakupa option moja tu ya ku click ok inadisappear for 1sec then inakuja tena...so cant login...huwezi kwenda kwa safe mode wala option nyingine yoyote coz huko napo ipo!! anyone knows how to solve this kabla sijapiga mashine chini!!