Epson Printer Driver Installation in Windows 10 (Epson L121)

I have encountered this with HP printers that refuse to install correctly, notably the newer 2016+ HP DS models. It's really bad on the newer HP DS firmware in general compared to the legacy HP firmware which didn't have DS, to the point I have had to reset one I picked (before I realized how bad HP DS firmware is, HP sold me on it because of how good the M401/M425 was) so many times that I check the behavior for a match, do a network reset, issue a new static IP, and then edit the port on the PC. The HP DS firmware has an awful network/print layer stack because HP focuses its energy on blocking third-party toner/ink, not on making the network stack reliable. AND IF the port edit doesn't fix it, I need to delete and re-add it, and after so many, clear the registry of any printer queue pileup.

First, go into the device manager, look for Printers and Print queues, and purge all but Microsoft Print to PDF. Once you do that, restart the PC and reinstall it. If the problem persists, you have to do it in the registry.

If it comes to a point where there is some printer pileup in the registry, you may have to uninstall the Epson driver, then delete every Epson printer from the registry. Leave Microsoft Print to PDF be, but anything Epson related for printers has to go. This does work, as it is how I have had to fix the connection issue on the HP DS machines one too many times. After removal, restart the PC and re-add the printers from scratch. You need to reboot the system before reinstalling it, as this is the only way to clear the problematic queue "memory. This fix is only needed with serious backups, so you should not have to do this regularly. If you do, your OS is partially broken, or the printer has hot garbage firmware. This is a "all else fails" solution - not a first line solution*.
*Yes, I use this as a first-line fix once I know I've re-added the HP M426 I use this workaround on, but that printer has horrible firmware, and I sometimes have had to do it 2-3 times, and it likes to hang on bad queues after that.

Here is the registry set where the printers are in Windows: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Printers - once you find it, delete everything but Microsoft Print to PDF.

It will be located here in the registry. Just delete the entry, not the entire folder: