Well, is it a silent installer, then? Because double clicking the installer does not bring up a visible window or anything
Try to run it from the administrator.
https://www.youtube.com/watch?v=OH4-hYT7Vgo
Check your computer for viruses. Maybe you caught the virus - 'Neshta'.
I ran the boot and full check with my Avast Internet Security, both came up clear. No viruses.
Forget it, i'll just play something else