Alright.
Windows 10 has a lot of Common issues with gaming , in short don't use windows 10 a lot of gaming since it has so many bugs n stuffs.
This is also a common issue and happened to me also when I installed windows 10.
To fix this , First get CLEO , install it and you should have asi with it when you install it.
Then you need Silent Patch for GTA SA , search it on google , download it and put it in your gta sa directory , inside the folder.
This should work.
Cheers!