Hhmm.... Do you still have the problem after restarting the computer? Do you find the Task Manager shows Inkscape is running, before you try to open it? Or does it only show that it is running after you try to open, but you still don't have the window?
The first time you open Inkscape after installing it, it takes longer than you might expect, to open. If you have a lot of fonts installed, it might take a full minute or 2 for the fonts to load. But after the first time, it loads much faster.
Have you waited, but it still doesn't show?