Windows 7 Home Premium Factory Restore

Hi

I need to restore my Windows 7 Home Premium at Dell Studio 1555. I do have recovery partition at my system and hove worked on the following but was unsuccessful:

1. I booted my laptop in advanced boot options and selected repair your computer. The system goes with the Windows normal and nothing happens.

2. I've tried the Dell safe local backup utility for the same purpose. The system restarts in the recovery mode but halts with error

Info: the selected entry could not be loaded because the application is missing or corrupt. Error message code is 0xc0000001. \windows\system32\boot\winload.exe was missing.

3. I've use the dell safe local backup to create recovery at USB drive. then booted it from the usb drive but ended in the same as above.

Can someone help me in this regard?