The Windows operating sustem appears to be corrupted and most like to get a working computer you need to restore it back to the factore default condition.
Before you attemp to do this and to back up data, remove the hard disk from the Toshiba and connect this hard disk to an USB hard drive adapter, then plug this adapter into the USB port of a working computer. This computer will see this as an external storage device. You can then open the various folders on this drive and back up your data on this computer or an USB memory stick.
To restore your Toshiba, insert the hard disk back into the Toshiba and follow these instructions..
Restore Toshiba to Out of the Box Condition
If your model Toshiba laptop has a Restore partition on thehard drive then follow these steps to restore your Toshiba to the Out of theBox condition.
1. Press and hold the 0 (zero) key and at the same time, tap the power buttononce to switch on
2. When the machine Starts beeping; release the 0 key.
3. When prompted by the warning screen; select Yes to continue with the systemrecovery.
4. Select Recovery of Factory Default Software; click Next.
5. Select Recover to out-of-box state. 6. Click Next again.
7. Click Next to Start recovery.
8. Restart the Toshiba laptop when there restoration process finishes running.Follow the prompts that appear on the screen to set up the laptop's date, timeand language settings.http://www.fixya.com/support/r8248520-restore_toshiba_out_box_condition