After i used reset to factory settings on my dell laptop, it brought me back from win 8.1 to win 8. My C: was half full and found that the old windows system was still using around 120 GB from my space. Since i am planning to reinstall with Windows media tool using Windows 8.1 i had to upgrade to 8.1 again in order to start the reinstallation. The progress blocked at 82% and i read a few suggestions that it could be the charger (must be unplugged). I unplugged everything but it still remained blocked so i restarted it. It restored my windows 8 and i again found infromation that this Windows.old could be the reason why the upgrade stops at 82%. However, now after windows failed to upgrade me to 8.1 and restored to 8 this 120GB that were used by Windows.old is now free. Does that mean that it deleted itself. Shall i try to upgrade it again?