My acer recovery management is not working

[hpam]

HELP!!!!! some files that had extensions enabling my applications to start properly were deleted accidentally. i'm not able to perform system recovery, as a result. is their a back door solution to perform system recovery for my acer aspire one?

 

[nhasian]

Here are detailed step by step instructions with pictures:

How Do I Use the Windows System Restore Utility?
How Do I Perform a Startup Repair or Repair Installation of Windows?
How Do I Perform a Clean Installation of Windows?

Also there is SFC How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7