Before we look at the "how," we must understand the "what." Most retail traders visit a broker’s website and click the bright orange "Download MT4" button. This usually downloads a tiny .exe file (often less than 5 MB).
Once installed, go to Tools > Options > Expert Advisors. Ensure "Allow automated trading" is checked. Then, go to Charts > Properties and adjust your color scheme. metatrader 4 windows offline installer