How do you verify a restore?

There are a variety of tools available on Linux which are well-suited to this task. You can use mount.cifs to mount Windows shared folders on a Linux host, or you could just run Cygwin right on the file server.

Before starting the backup, use the find command to recursively iterate from a specified directory and write the results to a file. This listing can be saved along with the backup for future use.

find /path/to/dir > list_before.txt

If you want to have checksums calculated for every file, just pass the output through md5. This command only shows filenames because folders don't need hashes.

find /path/to/dir -type f -print0 | xargs -0 md5 > md5_before.txt

After restoring the backup, build another file list using the same command, then use diff to find differences between them. Ideally, this command should give no output.

diff list_before.txt list_after.txt