But that file was so much smaller that the reg-file should be.
Can I use the system.bak if I have one for something?
If the file is smaller than your current system.dat file then I don't recommend using it. It must be an old backup of the file so it could cause problems.
If you are feeling brave you could try making a copy of both files, then rename system.bak to system.dat and see if you can boot. If it fails then copy the old system.dat back over it.
If you ghost an image or make a Winbased backup, how much space does it take and how much does it backup...what kind/type of files?
If you Ghost a hard drive it creates an exact disk image onto another drive. This means you could connect that second drive as master and literally boot up with it. (if the windows worked of course)
More info:
A win-based backup is different, you choose which files/folders you would like to backup and tell the program where you want to back them up to (floppy, hard drive e.t.c)
It creates a file with an extension of .bkf
More info here: