By automatically starting the MetaTrader, you don’t need to login into your VPS and start your MT4/5 instance again. It will be started automatically after a reboot as well. Please refer to the following steps to set up MetaTrader 4 or 5 automatically starting after a VPS reboot.
1. Log in to your Windows VPS.
2. Go to Start >> Run and type shell:common startup and click on the OK button. 
3. It will open the Startup dialogue box. Right-click and select New >> Shortcut
4. Click on the browse button, select metatrader5, and click on the Next button.
5. Give your shortcut name and click on the finish button.
Now your VPS is rebooted, so when you start your Forex VPS, the Meta trader instance will be started automatically.