Atleast don't post piracy links here
Whenever I alt+tab while logged in SA-MP I only get a black screen. CTRL+ALT+DEL does not work and the only way to get rid of it is to alt+tab back into the game.
Black screen in the game or desktop? Try some of these:
- Remove any available graphics & steam fix mods
- Set Program Compatibility to Windows 7 and Run as Administrator
- Removing sa-mp.cfg in
"My Documents\GTA San Andreas User Files\SAMP" directory
- Reinstall SA-MP
- Still not working? Revert all the options back to normal

Have you tried setting the game quality to low and low down the resolution?