Please Help me. I can't access any file on my computer

Please Help me. I can’t access any file on my computer. The other night I installed the latest Comodo Firewall, that I downloaded from the Comodo site. I don’t know what rule I set. I am using Blackbox4Windows (A Shell replacer). Today I did a restart of the computer and when windows begins I couldn’t access any file on my computer, even if I use run. How can I revert all to the defaults. Without enter in to normal windows, I am a little noob in this. I was trying do a restoration of the system, but don’t know how to do this. Maybe everything that is skinned by BB4Win is been not allowed. ??? :frowning:
Could be some virus? And this have nothing related to Comodo? BB4Win loads and then everything is blocked. Since then I’ve benn using Comodo 2. Yesterday when I installed everthing was working fine.
Ok. (L) I solved, I just quit the shell, then I can open explorer, open Comodo, etc…
Another question is: How I sent back comodo to his defaults settings? I mean: to when it was when I installed it? Maybe I need to read the manual. Thanks for Comodo, great firewall. I was not testing with this. :-[

Go to Defense+ → Advanced → Computer security policy → see if you have anything put to be blocked. Try unblocking Windows related items.