Method One,
Set up the optical drive to boot, then put the Win7 system installation disk, for system repair.
Method Two,
When the Windows7 system is powered on, hold down the F8 key, select "Safe Mode" in the Windows Advanced Boot Options interface, and then enter Safe mode to restart the computer, restart and hold the F8 key again, and in the Windows Advanced Startup options interface, select " Last Known Good Configuration, and press ENTER.
Methods Three,
If your win7 System Restore function is turned on, then press and hold F8 key, select "Safe Mode", in Safe mode for System Restore operation, the specific operation is as follows:
1, first enter the "Safe mode" and then click "Start"--"All Programs"-"attachment"-"System Tools"-"System Restore", open the System Restore Wizard;
2, then select the "Restore my Computer to an earlier time" option, click the "Next" button, on the calendar to click on the date displayed in bold text, select System Restore point, click the "Next" button can be System Restore.
Method Four,
Back up the important files stored in the system disk and try to reinstall the system if your computer is over 2G of memory