I recently installed a firewall and downloaded the security updates from the Microsoft website. I am unable to open my email program, even when offline. It says it cannot load one of the .dll files (though the file exists in a folder).
It depends on the program.
In this case, ideally we’d get a little more information, but lets see how far we can get and come up with some general troubleshooting rules along the way.
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“It cannot load the DLL” could mean several things and unfortunately, we don’t know what the exact error message was. If it couldn’t find it, it’s possible that the DLL is simply in the wrong place since the person asking pointed out that it was on the disk. If it had a problem loading it, then perhaps it’s corrupt or perhaps it’s in use by some other application.
For a missing, misplaced, or corrupt DLL, reinstalling or repairing the application is often the right course of action. It’s possible that this is a window DLL, in which case a System File Check might repair the problem.
If it’s a DLL relating to your email program then reinstalling that could be the right way to proceed.
If the DLL is in use by another program it’s possible that program has locked access to it for some reason. The techniques in the previous article How can I find out who is using a “file in
use”? can be used to determine who’s using a DLL. Perhaps shutting down that program, if possible, will allow you to start your email.
And of course, it’s quite possible that it’s none of the above. Error messages typically contain important information to help track down these types of things, so we’d probably need to see the specifics to make a further determination.