after instaling the OS X EI Capitan system got restarted there after its keep on geting restarting continuesly i am not geting any option to go back to the previous version and data
MacBook Air, Mac OS X (10.4.2)
Reinstall El Capitan Without Erasing the Drive
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears.
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the indented Macintosh HD entry from the the left side list. Click on the First Aid button in the toolbar. Wait until the operation completes, then quit Disk Utility and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Continue button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless and more reliable.
Follow the instructions here > OS X: When your computer spontaneously restarts
mac book air is keep on geting restart
