Your computer may be unable to boot due to an error with its hard drive. To resolve this issue, you will need to buy a Windows rescue DVD for the version of Windows that you have on your computer. You can find inexpensive Windows DVDs at Walmart or on Amazon or other retail websites. Insert the DVD into your computer, start it, and follow the DVD’s onscreen instructions.
If your computer fails to boot after you have run the DVD, or if your computer will not boot after insertion of the DVD, then you may need to replace your hard drive.
Try checking out our [[Toshiba Satellite A665-S5170 Troubleshooting|troubleshooting guide]] for the Toshiba Satellite A665-S5170 if you have any more questions!