I just write a simple dos bat file that renames the files and deletes the older ones
But I have a sneaky suspiscion that if you have a system drive and data drive in the one backup job any post/pre commands are run each time for each drive which throws everything out for the script, but i haven't actually verify it to be so, just a gut feeling so i run separate backup jobs for the system and data drives and depending on if you have enough room or not I either delete the oldest image in pre command or in the post command if theres plenty of room for the current and previous backups. and i just run the script on the last job only. But had a problem on on site where the two jobs were clashing and the script wasnt executing cause the last job was terminating. which left the drive full after a few weeks. once i spaced out the backup times its all good.
Anyway enough of my rambling
My script just does this
del c_backup5.spf (No this command could be run in the pre backup command to allow for more backup images on the drive)
ren c_backup4.spf backup5.spf
ren c_backup3.spf backup4.spf
ren c_backup2.spf backup3.spf
ren c_backup1.spf backup2.spf
ren c_vol*.spf backup1.spf
do the same for any other Hard drive volume image sets
So who needs vbscripts anyway