For some programs 'ubinstall' does not work

I have windows 8 (came pre-installed); recently upgraded to windows 8.1. I have tried uninstalling AVG and some other programs, but uninstall does not work. I shall appreciate help in this matter. Un-install seems to start but never gets completed. Windows defender is active and windows firewall is on. So my computer is protected. AVG is not running, as the Task Manager does not list it.

Some time back, I had reported at this site that I-Explorer keeps shutting down. That problem does not exist anymore. I did not do anything to correct it. I shall appreciate hearing an explanation for this welcome resolution.

Thanks.
Preet