hi
DCA 6.0.6 is the one supported on Windows 7... for XP, something is interfering wiht DCA to come up.
Are you also running the NBX Complement Attendant software (CAS)? DCA and CAS cannot be run at the same time. Also, what version of TSP are you running. DCA runs on TSP.
Check your virus protection software.... sometimes that has interfered with TSP starting, thus DCA would not start.
To get DCA 6.0.6, you should go to your HP Passport site.
You can also get it from the following ftp site that I try to keep up.
ftp.usa.hp.com
Login: nbx12345
pass Winter12
Copy over DCA 6.0.6 and install on both xp and win 7 machines... Let us know how this goes