Since you cannot download the modern Quick Assist app from the Microsoft Store for Windows 8, you should use the pre-installed tool. 1. How to Launch Remote Assistance
Quick Assist for Windows 8: How to Get Remote Help on Older Systems download quick assist for windows 8
However, this doesn't mean you can't get or give remote help on a Windows 8 or 8.1 machine. Windows 8 comes with a built-in predecessor called that provides almost identical functionality. How to Use "Quick Assist" (Remote Assistance) on Windows 8 Since you cannot download the modern Quick Assist