When I try to open "Start Tor Browser.exe" the error message
"Firefox is already running, but not responding. To open a new window, you must first close the existing Firefox process, or restart your system."
It appears that I don't have any Firefox window open and in the taskmanager there is no Firefox process until I try to open Tor. The process is firefox.exe and the description says "TorBrowser". When I close the error message this process disappears. I read in other questions, that this problem is connected with Tor being installed in the "program files" folder, but I installed it in a different folder on the hard drive.
Yesterday I installed the newest available Version of Firefox (i.e. 28.0) and of the tor-browser-bundle (i.e. 3.5.3). Yesterday I could use it without problems. Then I hid the folder and turned off the computer. And today it didn't work no matter if the folder was hidden or not. I also tried to restart the computer.
I'm working on Windows 7 64 bit. Does anyone has an idea how I could solve this problem or what the cause could be?