Hidden explorer.exe windows
 

So sometimes when I click on a shortcut on my desktop to a folder, it won't open. And when I open up taskmanager it shows several instances of explorer.exe, but the windows are hidden and I can't switch to them.

Now I know that one instance is the shell, the one with normal priority.

So I usually close all the high priority instances of explorer.exe and then I can open the explorer file manager. Or sometimes it seems that if I have 2 hidden explorer.exe instances and kill one, then the other one will become visible, like it was stuck or something.

Could this be some sort of virus or trojan? I have a lot of virus/trojan software and scan a lot and have real time protection so I don't think so.

But it is annoying.

Any suggestions?

I was thinking of downloading one of those file firewall type programs where anytime a program tries to start up you have to click the pop up to give it permission, like a firewall. In case something is spawning hidden windows or something.