I have something similar, I had problems opening firefox nothing would happen so I trued to uninstall it and it tells me that I have firefox open when in fact I was using internet explorer not firefox. When I went to check to make sure there was nothing open it was blank. How do I clear this to uninstall firefox?

Firefox Hangs at Exit

https://support.mozilla.com/en-US/kb/Firefox%20hangs#w_hang-at-exit

Check and tell if its working.

my problem now is in the installation. Nothing happens.

Go through theses article one by one

Uninstalling Firefox

https://support.mozilla.com/en-US/kb/Uninstalling%20Firefox

Firefox Setup.exe won't run

https://support.mozilla.com/en-US/kb/Firefox%20is%20reported%20to%20be%20infected%20with%20a%20trojan%20or%20virus

Installing Firefox on Windows

https://support.mozilla.com/en-US/kb/Installing%20Firefox%20on%20Windows

Check and tell if its working,

I had trouble with the previous version, so i try to install again but kept on saying "run as a. current user or b. run the program as the following user". I picked current user but nothing happens. what should I do?

did you tryout the suggestions written in the articles mentioned in my previous post ??

all tried, no luck. do i have to reboot my computer again?

Is my Firefox problem a result of Malware ?

https://support.mozilla.com/en-US/kb/Is%20my%20Firefox%20problem%20a%20result%20of%20malware

Check and tell if its working.