❓ Issue with OKI C650 Drivers on Windows 10 & 11 – PS vs PCL6

[kmmp]

Hi everyone,


I’m facing a persistent driver issue with my OKI C650 printer on both Windows 10 and Windows 11.

• When I manually install the official OKI C650 PS (PostScript) driver (from the manufacturer, with INF/CAT/VER files), Windows keeps overriding it after reboot and forces the generic Microsoft printqueue.inf driver dated 2006.
• Even when using pnputil to delete older entries, or forcing installation via "Add Printer" > "Have Disk", Windows says "best driver already installed" and won’t let me keep the OKI PS driver.
• I tried both USB and network connections – same result.
• However, the PCL6 driver works perfectly: it stays in place, offers a much richer print panel (toner options, color control, etc.), and doesn’t get overridden.

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Questions​

1. Why is Windows overriding the PostScript driver even though it’s signed and valid?
2. Is there a reliable method to permanently enforce the use of the OKI PS driver?
3. Are there any clear advantages of using PS over PCL6 for this printer (in real-world usage with PDFs, high-quality graphics, etc.), or is PCL6 actually the better/recommended choice?

Thanks in advance for any help or insights!