Go to the WCH official site (search "WCH CH351 driver") or grab it from a trusted repository like wch-ic.com . Look for the file named CH35XDRV.EXE or CH351PAR.EXE . As of this writing, version 1.30 or newer works best on Windows 10/11.
The CH351Q driver package supports a broad range of operating systems: ch351q parallel port driver
Legacy software often expects communication over standard hardware addresses (like 0x378 for LPT1 or 0x278 for LPT2). PCI-based cards use dynamic I/O addressing assigned by the motherboard's BIOS/UEFI, which can cause software conflicts. Changing the LPT Port Number Go to the WCH official site (search "WCH