If you want to image the system so it can be returned to a condition where the HP recovery procedure works, even if the hard drive has to be replaced for failure, then image the entire hard drive with all four partitions. It will not make the image that much larger. If you don't want to preserve the HP restore capability if the hard drive gets corrupted, then they could be excluded.
As a minimum, you need the first and second partitions - the System partition contains system bootup files and space for some Win7 functions like Bitlocker if you ever use it, and C: of course has everything else.
Edited by Platypus, 27 January 2010 - 08:36 AM.