After the printer is installed, you need to make sure that the correct page layout is set on a printer for POS receipts:

1. Open up Control Panel > Devices and Printer
2. Right mouse click on installed printer > Printer Properties
   

Go to Preferences

Go to Advanced

Select Paper Size: 72mm x Receipt and press OK

Go back on Printer Properties > select Advanced tab > press Printing Defaults

Select Paper Size: 72mm x Receipt and press OK

Back on Printer Properties > select Device Settings tab > make sure 72mm x Receipt layout is selected and press OK.