: Windows cannot replace or modify core files while they are actively running or "locked" by a process. A restart ensures that no programs are using the old driver files, allowing the system to safely swap them for the new versions during the boot sequence.
: On modern systems like Windows 10/11, you can often install multiple drivers and reboot just once at the very end to finalize everything.
Restarting the actual printer hardware is often a separate troubleshooting step to clear its internal memory (RAM).
– Do it only after the driver installation is complete. Power off the printer, wait 10 seconds, and power it on. This clears any stale network or USB handshake data.