OBS is good but took me time and attempt to setup working correctly.
Windows Plays.tv is easy but not many configuration option.
ShadowPlay is good alternative also.
Have you try obs to work before? obs quite good when working
I forget. I am not good to configure to be useful for instruction.
I try many method.
window mode - capture window
full screen - capture window
move target application up and down list
I also not get it to work on one game particular.... I forget the name... I think it was game fault maybe.
Its for nvideo cards. It is smooth and quick. Sometime some game I will have performance using obs and need to find setting. shadowplay sometime work better but not always. I use obs more so less familar but use as another solution when obs not
OBS is your best bet for no cost. Look up some guides on how to get started with it. It's both a streaming and recording tool.
Just add a game capture object under your sources. Would highly recommend having a dual monitor setup if you plan to do any of this sort of stuff as it just makes life a lot easier.
If you don't have a fairly recent NVidia card that supports NVENC or higher end Intel processor that has a built-in GPU with QSV, you're going to have to rely purely on your CPU to encode the video on the fly which most machines can't handle on top of the resources needed to render a modern game.
If OBS is setup correctly and you're still getting a black screen, try using display or window capture instead of game.
If you have an Nvidia card ShadowPlay is actually one of the best options out there despite its wonky interface. It has the least strain on your system and its compression algorithm is surprisingly good in minimizing losses. You just need a separate program to edit the videos it recorded.
Do you computer support window 10? I have so many problem on 8 I change back to 7 for many years more. Then change direct to window 10. I still prefer 7 usage in many way but 10 is better than 8. I think many part should be able handle win 10 now.
If you don't mind idea maybe try. back up some important stuff always. roll back if no good. maybe this link helpful
Here's how you can still get a free Windows 10 upgrade | ZDNet