I can't comment on Windows 10 because I don't use it and probably never will, but if you poke around on the Nik web site you'll find that the filters do run on Windows 10 but that Google hasn't done any testing on that platform. At this point I very much doubt if they ever will. In any case...
On your system, if you go to computer and then open your 'C' drive you should see a bunch of folders. I don't know whether or not you're using a 64 bit OS but assuming you are, look for a folder named Program Files. From there go to...
- Nik Colllection
- Analog Efex Pro 2
- Color Efex Pro 4
- Dfine 2
- HDR Efex Pro 2
- Sharpener Pro 2
- Silver Efex Pro 3
- Viveza 2
Inside each folder you should find one or (in the case of Sharpener Pro 2) two exe files. Those are the actual applications. Just double click whichever one you wish to run. Personally, if I were going to run them this way, I would make shortcuts of each application and place them in a folder on the desktop for easy access.
Of course it would still be better if you had a host application to run them from. Once more, I encourage you to either purchase Adobe Photoshop Elements (which can be had for between $40 and $100 depending on whether or not it's on sale or sign up for the Adobe Photography Plan which gives you both Photoshop CC (full version) and Lightroom CC (again, the full version) for US$10 a month.