It is possible that it cannot run the install program. The reason might be that it cannot find the program file, or you do not have permissions, or something else. Rather than trying to guess the reason though, it would be better to test the exit code in $? after the `back-ticks` command.

Since you are running on Windows, make sure you are running this from CMD.EXE, not by double-clicking from Windows Explorer. Sometimes an error message is written directly to the console by the Windows shell, by-passing STDOUT and STDERR, for example

'install' is not recognized as an internal or external command,
operable program or batch file.
[download]

and that might be missed.