Okay I can not start up my windows computer, there are some impotant data in my computer, and want to get back these data, but i have no idea, so i turned for somebody, he gave me two answers.Answer One: Recover Windows Data in Safe Mode
If it still won't boot properly, reboot and go to the Advanced Options menu again. This time, choose Safe Mode and press Enter. Windows starting in Safe Mode automatically skips loading programs and hardware components and displays very primitive graphics. In 99% of the cases, it'll fix the problem. If your computer starts up properly, uninstall programs you installed or undo any changes you made recently. Then, restart your computer normally.
Answer Two: Recover Windows Data with Data Recovery WinPE
* Step 1: Download Tenorshare Data Recovery WinPE in any available computer (not from PC that can't boot up). Then launch it.
* Step 2: Insert CD/DVD/USB flash drive to the computer, choose ISO image file. Here take USB flash drive for example. Burn ISO file into flash drive.
* Step 3: Insert the burned flash drive to the unbootable PC. Run computer and press "F2", "F10" or "Delete" to enter BIOS setup.
* Step 4: Use the arrow keys to select Boot tab, select Boot Device Priority and press Enter. Please choose 1st Boot Device to USB, and then press F10 to save setting. Now your computer will start with the changed settings automatically. After restarting your computer, you will see the interface of Tenorshare Data Recovery WinPE.
Thank for his help, i get back my data, i think the second methods wich is very quickly to get back data by data recovery for winpe, i enjoy the procedures.
Source: http://www.any-data-recovery.com/product/datarecoverywinpe.htm