What happens if you allow and monitor/exclude sandboxie?
...Solution: Adjust shield settings in BitDefender. Open main window, click the Settings icon, click the Antivirus Shield button. In the Shield tab of the ANTIVIRUS SETTINGS window, find the Active Virus Control title and move the slider on the right to OFF. (Note: This is the ON-OFF slider, not the Agressive-Normal-Permissive slider.)"
http://www.sandboxie.com/index.php?KnownConflicts#bitdefender
Was this of any help?
Trust venustus, you'll thank him later!

Suma, I feel you've placed a lot of trust in BitDefender as have I. I had their free version installed on my Windows 8.1 back in December. I'd then mistakenly

blamed Zemana Anti-logger as being the culprit of incompatibility until Exterminator20 helped me to discern (before I could abruptly uninstall the Anti-logger) that my BitDefender AV had been incompatible with Windows 8.1 system at that time. I urge you to follow the advice of both venustus & bo.elam. Sandboxie is not malware. It's proven itself rather to be an indispensable reason that all three computers in my home (an old XP, Win 7, & Win 8.1) are running trouble free, and with a peace of mind for me!

Do give it a try.
Cats, ...Someone that uses Sandboxie like I do, never stops using SBIE. When I get a file out of the sandbox, I continue running those files sandboxed by either using the Forced folder feature (in the Downloads folder) or the Forced programs feature when I move them away from the download folder.
Using Sandboxie is like a process, the only time that I run files out of the sandbox is when I install something in my real system (something extremely rare). Files in my computers run sandboxed from the day they are downloaded to the day they get deleted. There are exceptions but they are rare.
Doing the above is what I call: Getting every drop of juice out of Sandboxie. The good thing is that much of what I just wrote can be done with the free version, users with the free version just have to know how to get it done. Using a sandboxed Windows explorer and creating and using sandboxed shortcuts are tools that can be used to achieve much of what I am saying. These tools are available for everyone that installs SBIE.
Bo
Thanks for relating all this, Bo!

I'd like "
Getting every drop of juice..." too (Mm,
Sandbox juice!

). Usually... in fact,
always I <delete> the sandbox at the end of browsing sessions. In case I forget, I have Sandboxie set to delete files when closed. So, do files remain isolated in the sandbox even when you shut down the system? Two of our systems shut down 4Xs during the evening (& night) before yesterday because of power outages

, & this during Windows Security Updates no less!

Often I'll set our computers to sleep or hibernate, so except when performing upgrades for extensions or browsers, Iill always open them sandboxed. Sometimes, I wonder "
..maybe, I might not even have to use browser extensions or
update Firefox again", and experience what Umbra Polaris expresses as "
Browsing light & free!", lol!

What do you think of VM?

(I read a post about it earlier)