Ok, it sounds like you are dealing with a fragged hard drive, or corrupted system files. Boot into safe mode, does it boot faster?
Reverting a fragged drive back does not help the operation, it just makes matter worse. Open up the file manager, how much free space is on the C drive? If it is less than 20% free, then you need to free up some space, defrag the drive, run chkdsk, then SFC /scannow.