About the VLC issue, could be a codec.. But, I use VLC and didn't ever downloaded a codec pack in adition, so, reinstall VLC or just reinstall the codec pack you could have.
If you have a "program" poped up while gaming, then maybe its a process/software associated to a 3D enviroment, and at the moment you start a game then its shows up. Specially if it happens on any game. If not, then maybe its a problem from that game only..
You could also try Ctrl+Alt+Del/Task Manager, and in the Processes Tab see all the services/programs running while gaming. Then, go into the game and exit and see which ones ended too.. Maybe one of them is making you annoying..
8320 @ 4,7 / 990FXA UD5 / 7950 @ 1100-6000 / Switch 810 / H110 p-p / 16 GB RAM / 23" 5760x1080 / SSD 64GB RAID0 / HX750 / SB Recon3D Fatal1ty Champion / z506