Transparent file restore

1. A method for automatically handling an error when retrieving a file for an application, comprising:

under control of a file restore filter that is an extension to an operating system:

detecting the error when the application attempts to retrieve the file from a storage device by intercepting an error message;

checking a user defined policy to determine whether a backup copy should be restored, wherein the user defined policy indicates when the backup copy should be used in one of multiple circumstances based on whether the error is caused by a damaged file or by a missing file and based on whether modifications were made to the file since the backup copy was made; and

restoring the file from the backup copy if the user defined policy indicates that the backup copy should be used, wherein the application proceeds with the file restored from the backup copy without failing due to the error.

2. The method of claim 1 , further comprising:

locating a backup copy of the file if one backup copy is exists, wherein the user defined policy is checked and the file restored if the backup copy exists.

3. The method of claim 1 , further comprising:

determining whether the file has been modified since the backup copy was made.

4. The method of claim 1 , further comprising:

monitoring all modifications to files in a change log; and

monitoring all file retrievals for errors.

5. The method of claim 4 , further comprising:

determining whether the file has been modified since the backup copy was made by comparing a modification date in the change log and the time of when the backup copy was made.

6. The method of claim 1 , wherein providing the backup copy according to the user defined policy further comprises:

providing the backup copy to the application if the user defined policy authorizes use of the backup copy; and

providing an error message without the backup copy to the application if the user defined policy does not authorize the backup copy.

7. The method of claim 6 , further comprises:

verifying access authorization before providing the backup copy.

8. The method of claim 1 , wherein a default setting for the user defined policy is to automatically restore the backup file copy.

9. The method of claim 1 , wherein checking a user defined policy to determine whether the backup copy should be used only occurs if the file has been modified since the backup copy was made.