Robocopy is a great tool for copying files and is built into Vista. As a reference here is some information on the exit codes (not error codes – they provide information about what the program did), from http://kerpau.net/robocopy-exit-codes/

The return code from Robocopy is a bit map, defined as follows:

Hex Bit Value Decimal Value Meaning If Set

0×10 16 Serious error. Robocopy did not copy any files. This is either a usage error or an error due to insufficient access privileges on the source or destination directories.

0×08 8 Some files or directories could not be copied (copy errors occurred and the retry limit was exceeded). Check these errors further.

0×04 4 Some Mismatched files or directories were detected. Examine the output log. Housekeeping is probably necessary.

0×02 2 Some Extra files or directories were detected. Examine the output log. Some housekeeping may be needed.

0×01 1 One or more files were copied successfully (that is, new files have arrived).

0×00 0 No errors occurred, and no copying was done. The source and destination directory trees are completely synchronized.

You might get a code not listed here, like 3. If this is the case, all of the codes that add up to the value you received happened. Exit code 3 indicates that files were copied and that extra directories were detected. This might happen if you’re backing up a folder. I’ll talk about using robocopy for vista backups next time.