Installed LibreOffice 4.4.1.2 on Windows 8.1 but on launch nothing happens. What do I need to do?

I’ve installed LibreOffice on my new Windows 8.1 laptop. On the programmes list from the start menu it shows as an installed version (4.4.1.2), but when I try to launch it to open either a Word document or an Excel document - nothing happens. What have I done wrong? How can I fix this?

I am using the same version of LibreOffice on Windows 8 without any problems. I remember it took some time to open the first time I used it - does it show in Task manager?

Peter