The Issue:
- When launching SWAT 4 (even for the first time), nothing happens.
- Splash Screen might appear after several minutes or not at all
- When viewed in task manager the Swat 4 process* will take up considerable CPU power
* (to be precise: it's the rundll32 sub-process)

Solution:
Described here, fourth from the top.
Quoted:
This might be caused by a glitched dll in the Windows compatibility layer.
If you have 64bit OS, go to windows\syswow64\ and rename gameux.dll to something without .dll extension
If you have 32bit OS, go to windows\system32\ and rename gameux.dll to something without .dll extension
In both cases you'll have to take ownership of the file to move it. See more


Hope this helps someone, I was growing rather irritated.

This was exactly the problem I had. Thanks for this!