Backup lost ? "backup file contains unrecognized...."

[Magnus]

Hi,

I have done a backup on XP SP1 (just before a disk-
krasch) which I moved of to CD-RW. I used the backup
included in XP, saved it to a separate directory and the
burnt a cd with it.

I have now re-installed XP SP1 but I cant use the backup,
I can see the file, copy it to the harddisk etc. but all
I get is "the backup file contains unrecognized data and
cannot be used".

Any ideas on how to salvage it?

/magnus