We have seen a few instances where CrashPlan hangs during registration when an old version of CrashPlan is used during installation/registration.
To resolve this, you'll need to reinstall CrashPlan using the latest version from the IS&T Software Grid
Note: If CrashPlan still hangs during registration, you may need to do a complete uninstall of CrashPlan
(Contact the Service Desk if you need help with the complete uninstall.)
After you have done a complete uninstall of CrashPlan, reinstall it using the latest version.