I have observed a strange behaviour (may be a bug) on my friends computer when I installed CIS on it.
Whenever I right click on any drive and choose to scan with Comodo Antivirus, the scan window just flashes and immediately shrinks to something shown in below screenshot. There is no way to resize or restore it. If I try to close the window, it asks for stopping the scan, which means that the scan is running fine.
If you have time I would consider trying a uninstall/reinstall with a freshly downloaded installer in case of some form of corruption happened during install.
If the above fails there could be something unique between that particular system and CIS causing a conflict and for this reason I would consider filing a Bug Report in the hope of finding the cause.
If you do file a Bug Report please follow the Bug Report Format.
I will go with the first choice, I will do a fresh install again and see what happens.
I actually thought of filing a bug report and that is why I posted this issue, but I soon realised that we are soon going to have a complete new UI for next version…so may be this is not of much importance. So, I would file a bug report only if it is necessary.