Before I installed Windows 10, I was using Windows 8.1

When I opened Screen Resolution and went to advanced settings this is what it recorded:

Total Available Graphics Memory: 4000 MB

Dedicated Video Memory: 2500 MB

After Installing Windows 10 this all changed and has affected some of my programs and games. Now when I open the advanced settings it reads:

Total Available Graphics Memory: 1792 MB

Dedicated Video Memory: 32 MB

I've tried updating my drivers but nothing has worked. Mortal Kombat 9 is a game i really enjoyed playing but now doesn't open without some other annoying modifications. Most of the other games I install work properly but others not so much. Please any assistance to this problem will be greatly appreciated.