his problem have happened to me long time ago,
dont remember how do i fix it, but there is the possibility for a malware bloking the antivirus to connect
he need to do a full scan with many on demand scanners(hitman pro,malware byte, superantispyware)
these antivirus may not work also, in the worst case he will need to do a boot scan http://devbuilds.kaspersky-labs.com/devbuilds/RescueDisk10/kav_rescue_10.iso
also check the host file for no alteration
Not sure whether this would work or not. Having re-installed CIS (latest version), couldn’t you use GeekBuddy (if you installed duing installation of CIS) and have a COMODO technician remote in and diagnose the problem for you. I believe you get 60-days free support now.
I believe that if the manual update process gets as far as the “finalizing” stage, it has successfully downloaded some updates and is trying to apply them… and it’s failing to apply them in your case. There may be many reasons why.
One reason I found recently was a missing “C:\Windows\Temp” folder. Make sure your “C:\Windows\Temp” folder exists. If it doesn’t create a new folder by that name.