This is a character encoding mismatch. Go to Printer Properties > Preferences > Advanced > Character Set . Change it from "PC437" to "WPC1252" (Windows Western) or "UTF-8" depending on your POS software. Also, ensure your POS software is not sending raw ESC/POS commands to a Windows driver printer.
The download usually comes as a .zip or .rar archive. You must extract the files using a tool like WinRAR before running the XPrinter Driver Setup V7.77.exe . Xprinter Driver V7 77 Download Windows 7 32 Bit
Using the ensures: