My analog headphones and Stereo Mix icons aren't being detected in sound playback by Windows 8.1.

I'm using a Sony Vaio. This is the specific model:

https://esupport.sony.com/US/p/model-home.pl?mdl=SVS151290X

I'm having a problem with my analog headphones and Stereo Mix being detected in Sound Playback. The only thing is available is the RealTeak HD Audio. The reason I'm trying to get the other options working is that I've been utilizing a screen capture record program recently. I've tested a couple actually and I'm not able to record the PC sounds of a game or video or something when I screen record. I can record whatever the speaker and microphone picks up, but not the actual sounds from the PC itself.

Here is what I've done so far to try and fix the issue based on the information I've found online:

- Tried uninstalling the driver for the RealTek HD Audio and then reinstalling to latest update.
- Tried rolling back to an old driver for RealTek.
- Tried right clicking in the sound box to make sure that "Show Disabled Devices" and "Show Disconnected Devices" are checkmarked.

I'm not that tech savvy, so I'm not sure what to do at this point. I remember a while ago my computer was able to sound record. But that was probably when I had Windows 7 maybe. I can't remember. I did it about a year ago. Maybe it was Windows 8.

After doing more research I've heard that a lot of Sony's notebooks have Stereo Mix disabled, but there are apparently some people out there that have been able to enable it through certain drivers or something. And like I said about a year ago it worked for me when I screen recorded something. I think I was using Windows 8 at the time though instead of 8.1. But I know I definitely didn't have to to go to these lengths. Should I upgrade to Windows 10? Any help would greatly be appreciated. Thanks.