Como você tem um DELL PC / Laptop, tente estas etapas para restaurar a instalação de fábrica (se nada mais ajudar):
To restore your computer to the original factory installation, follow these steps:
Turn on the computer, after the Dell logo press F8 key repeatedly until the Advanced Boot Options menu (Advanced Startup Options). In Advanced Boot Options, highlight Repair Your Computer and press Enter. Click Next and logon to the administrator account in the computer. Click Dell DataSafe Restore and Emergency Backup and DataSafe Options. Choose Restore without preserving new or changed file. Click Next to continue. Choose Yes and click Next to continue. Progress status will appear. Click Restart to initiate the restoration process.