@Fluke32 , congratiulations first for your decision to go the right way! 
In cases like serious systems crashes, virus infections and other stuff like that, there is no reasonable way aside from starting over from scratch. Also, searching for the issue mostly takes more time and effort in the end and often is not guaranteed to work. A tip on that: be prepared! Do those backups and all …
On the topic: If that is a clean installation of Windows, normally the installation of FxSound should work fine and i have never experienced this issue reported here and there myself. That said, i am a technically relative experienced user, so i guess my case does not count here!
Generally speaking, i would first suggest the usual, if not done already: update ANYTHING (Windows, drivers, etc.) to have a solid base. Use the most current version of FxSound, of course. When it comes to device drivers, to not stick with the Windows default ones, if there is a better one from your hardware manufacturer — this alone can make the difference!
You already are aware that the Windows Device Manager is hiding devices and you cannot find FxSound there. Here is, what it should look like:
When a driver, what FxSound to some degree is in the end, is not loaded, it simply might be disabled for startup with Windows. Or its corresponding application. Check this in the Windows Task Manager and on the “Autostart” tab.
If you haven’t already, uninstalling FxSound completely and try reinstalling; sometimes there just went something wrong the first time even though there is no permanent problem which is not unusual on Windows. If your are experienced enough, check all the locations on your harddrive after uninstalling (Program Files, AppData, Registry, …) and then restart Windows before trying again.
If your are not using an admin account, try right-clicking the setup and “start as administrator”.
Reminds me that i need to find time to write those FAQs … 
And as always: the more and better informations you can give us, the better we can help you. Note down errors, make screenshots where possible, etc.