- You installed a mod that fucked your entire game up
- You're not running the correct version of GTA SA (It should be 1.0)
- If you're running the game on a pirated version, the pirate might be fucked
- Your compatibility mode is not working out for you, try fiddling around with it by right clicking on SAMP > Properties > Compatibility > Compatibility mode
If fiddling around in compatibility mode didn't work, try running GTA SA in single player to see if the game loads up fine.
If the single player works, try reinstalling samp.
If the single player didn't work, try reinstalling both GTA SA and samp.