Odd, there is still no tasklist in the log. Could you open a command prompt (Start -> run -> "cmd.exe" -> enter), enter "tasklist >C:\task.txt", then open C:\task.txt and paste its contents at Pastebin and link to it here?
Could you place https://nightly.multitheftauto.com/files/out/tasklist.exe into C:\WINDOWS\system32 then provide another MTADiag log? We really could use a process list.
Neither the audio driver nor the storage driver installed successfully, try installing them again please.
Does GTA:SA single player work without issues?
Please install the following:
Graphics driver
Audio driver
Chipset drivers
Ethernet driver (do a Repair install if prompted)
Storage driver
Provide another MTADiag log after installing.
Please download and run MTADiag and follow the instructions.
Also, stop using registry cleaners because they accomplish nothing at best, and can cause severe problems at worse. There is absolutely zero benefit to "optimizing" or "cleaning" the registry.
Click Start -> type Programs and Features -> hit Enter -> find Multi Theft Auto: San Andreas 1.3 in the list -> right click it -> click Uninstall -> follow the instructions. Then install MTA:SA again.
There are very few built-in commands. I believe typing /help ingame will provide a list of all built-in commands.
Any scripting must unfortunately be done via MTA:mA, which is based around mIRC scripting.