Suggestion:
(1) when you download, save to wherever - as the Download folder;
(2) close all opened programs;
(3) go to saved file;
(4) close folder, after clicking to install file;
(5) follow the instructions, as they come forth during the
installation;
(6) Voila ... the program should be now ready for your use.
If not, then try emptying the cache - as with CCleaner
If still not, then make sure the machine has not somehow picked up
some virus
Hoping this helps,