You plug in your trusty USB-to-serial adapter, and Windows 11 greets you with the infamous message: “This device cannot start. (Code 10)” — and in Device Manager, the adapter shows as “PL2303HXA PHASED OUT SINCE 2012. PLEASE CONTACT YOUR SUPPLIER.” Your cable didn’t break. Prolific deliberately disabled it. Here’s exactly why, and the fix that gets it working again in five minutes.
What actually happened
The original PL2303HXA and PL2303TA chips were cloned into oblivion. Prolific’s response was to build a counterfeit check into their newer Windows drivers: when a modern driver detects an old (or cloned) chip, it refuses to load and shows the “PHASED OUT” message — even on genuine older chips. Windows 11, always fetching the latest driver automatically, walked millions of working adapters straight into this wall.
The insight that fixes everything: the hardware is fine. The new driver is rejecting it. Install an older driver — from before the counterfeit check — and the adapter comes right back to life.
The fix, step by step
- Open Device Manager → Ports (COM & LPT) → right-click the “Prolific … PHASED OUT” device → Update driver;
- Choose Browse my computer for drivers → Let me pick from a list of available drivers on my computer;
- You’ll see a list of Prolific driver versions Windows already has. Pick an older one — version 3.3.11.152 (dated around 2008–2010) is the reliable choice. If several are listed, the oldest usually works;
- Click Next. The “PHASED OUT” message disappears and a working COM port appears;
- Stop Windows from re-breaking it: the auto-update will try to reinstall the new driver. Either set the port’s driver update to off, or use “Show or hide updates” to block the newer Prolific driver.
If no older driver is listed
Windows 11 clean installs sometimes only carry the new driver. Then you have two honest options:
- Get the legacy driver (v3.3.11.152) directly from Prolific’s own archive or a reputable source, then install via the manual “pick from list” route above. We link to Prolific’s official download page rather than re-hosting it — driver versions matter here and you want the genuine file;
- Or just replace the adapter. Honestly, the long-term fix: a CH340 or CP2102 adapter costs a couple of dollars and neither WCH nor Silicon Labs plays the counterfeit-lockout game. Many techs keep one Prolific cable working for legacy gear and buy CH340 for everything new.
Common questions
Is my chip genuine or fake? It often doesn’t matter — the new driver rejects many genuine old chips too. The older-driver fix works regardless.
Will the fix survive a reboot? Yes, as long as you blocked the automatic driver update. If “PHASED OUT” returns after a Windows update, Windows silently reinstalled the new driver — redo step 5.
macOS / Linux? Different driver stack; the “phased out” lockout is a Windows-driver behavior. On Linux the pl2303 kernel module generally just works.
Bottom line
Your adapter isn’t dead — it was politically retired. Roll back to an older Prolific driver and it works again in minutes. For anything new you build, save yourself the recurring headache and standardize on CH340 or CP2102 adapters.
