So i'm running a few .exe for strobe lights and rev bouncer and i manage to make them open with LFS with the autoexec.lfs but i can't figure how to make them close with LFS too.

Make a batch to close desired process and run it with /exec

Something like this?

Quote from mybatfile.bat :

@echo off
:onemoretime
tasklist /NH /FI "IMAGENAME eq LFS.exe" | find /i "LFS.exe" > nul && (
goto onemoretime)||(
taskkill /IM "RevBouncerV3.45.exe" /T
)

and add this at end of autoexec.lfs: /exec mybatfile.bat

Oh thanks Draggo! All i had to do was add the other process.