I suggest just to reinstall teh operation system and do not mind about else..cause it is not worth the effort ..if it is a software issue ..reinstalling it will solve the problem ..If you worry about the data on it ..just hook the hard disk to another computer (as secondary drive ) and copy all important data ..
After that just reinstall it using the recovery partition or disk or a boot-able disk with the OS .
If you do not have important info stored in C drive ..just reinstall without save ..cause the information in other partition will not be erase..just the C drive will be formatted ..