HP printer problem

My HP DeskJet 722C printer has been a workhorse, never failing me, so I
prefer not to replace it. The problem is that after replacing the color
cartridge, the low ink light continues to blink. So I got the bright idea to
remove the software and reinstall it (since I have the CD). Well it wouldn't
reinstall, and I'm thinking that since the drivers for this model are
included in Windows XP that it wouldn't completely reload. Now I'm stuck:
either purchase a new color cartridge (in case the one that I installed was
old or faulty) or get my printer analyzed. I prefer not to gamble on the
former, but I'm no printer psychotherapist. Any suggestions? Without a
complete software download, the 'troubleshooter' is unavailable to me for
help.