You can simply search for "Quick Assist" on Search or use the combination Ctrl + Win + Q to launch the app.

The next step depends on whether you're the one doing the helping or are being helped. The person doing the helping clicks "Help someone" on the app to generate a time-limited six-digit code, which they pass on by phone or by message.

The person on the other end, then, has to type in the code and allow screen sharing before anything shows up on the helper's screen. Once that's done, there's all there is to it. The helper can request control, and the sharer gets another prompt to either allow or deny. Nothing happens without the sharer's consent, and they can pull control back any time with "Cancel control." In the session, the helper also gets access to a few useful tools like a pointer, annotation tools, and a chat window for typed messages. //

Remote Desktop is unlike quick Assist, it's purpose-built for connecting to your own machines. The only catch is that it's limited to Windows 11 Pro and higher editions when it comes to hosting an RDP session, so if you want to reach your gaming PC from a laptop or jump into a Windows VM in Hyper-V, the host needs to be on Pro edition. The client side, however, works on any edition, so a Home machine can connect to a Pro host, just not the other way round.

Then, there's Windows Remote Assistant (msra.exe), which is the legacy option that predates Quick Assist by over a decade. The one real advantage it offers is that neither party needs a Microsoft account to use it. You can launch it from Run, send an invitation file, and the person on the other end can just connect with a password you've set. //

Ben
Rustdesk is my go to.

lacking a basic but very important feature "clipboard".