Cannot run Thunderbird outside the sandbox

Summary: I have a problem with Thunderbird. I can only run it within Comodo Sandbox, and cannot run it outside the sandbox.

System: Windows 7 64 bit Home Edition, Thunderbird 3.1.7, Comodo Firewall 5.3.176xxx.yyyy, Avast 5.1.889

Situation: On or about 12 Dec 2010, Thunderbird stopped working in the normal manner. When I try to start Thunderbird through shortcut, or by actually navigating to the .exe file, I get the message “Windows cannot access the specified device, path or file. You may not have the appropriate permissions to access this item.”
I have admin privileges on my machine. I have checked access privileges on the .exe, tried to run it “as administrator”. That does not work.

I have made Thunderbird a trusted application. In Defense+ under “unrecognized files” listing, there are no unrecognized files. In “Computer Security Policy” → Blocked Files, there are no files.

I uninstalled and reinstalled Thunderbird. When I did that, Thunderbird did start up out of the sandbox one time, right out of the install process (i.e. when it says …start Thunderbird? and I respond yes). Subsequent to that, when I tried to start Thunderbird again, it did not work and I got the above message.

I can still go to “Run program in a sandbox”, choose Thunderbird, run it with limited access and it runs fine.
I noticed that Comodo has created a separate location for my Thunderbird files here:
C:/VritualRoot/thunderbird.exe/HarddiskVolume3/Users//AppData/Local/Thunderbird
All my mail for the last couple of months is here.

Compare that to the one time when Thunderbird started outside the sandbox - the time when I reinstalled Thunderbird - the latest message in my mail there was from 12 Dec 2010. Those messages are at the normal location for Thunderbird:
C:/Users//AppData/Local/Thunderbird

When the misbehavior first happened, it was preceded by Comodo peppering me with questions about some processes. I was deep in the middle of another project and I may have answered no (i.e do not allow) to something to which I should not have said yes. I suspect that perhaps Thunderbird auto updater had updated the application or was trying to, and something did not go right. In the past Thunderbird had updated itself flawlessly.

I suppose I have the option of continuing to run Thunderbird from the Sandbox, but I would rather run it normally. I ignored the situation for a few weeks - obviously - but I think it is time to fix it.

Thank you for any or all help.

By the way, if I ever do get this fixed, I am then going to need help figuring out how to move or merge my mail from the ~/VritualRoot/~ location to the normal location for Thunderbird mail !

Thunderbird doesn’t get sandboxed here.

Hey and warm welcome to comodo forums user3945!

This is caused by Avast and not comodo. Add the avast folder to exclusions of Execution Control Settings in defense+ settings to ensure no high cpu usage.

I also suggest you go to avast forums and see what the avast user can do to help you.

I hope this will solve your problem.

Regards,
Valentin N