In my opinion, you can do these :
- make an image of your hard disk, using a tool like Norton Ghost or Clonezilla. Later if you want you can restore from that image
- create a slipstreamed DVD with all updates and hotfixes using vLite. This way next time you install Vista, all updates would be installed automatically
- if your bios supports some backup/recovery tool, you can create an extra hidden partition to save your present settings there. You can later do recovery from it.
CloneZilla -
http://www.clonezilla.org/
vLite -
http://www.vlite.net/