My PL2303 (USB/RS232) driver no longer loads. When I plug in the device, Vista goes to Windows Update for the driver and finds none. In Device Manager (DM), the annotation for the Port is Unknown device. When I try to manually install the driver through the DM, it fails. The code is sometimes 1 and other times 19, or 28), The error message is that some parts of the INF file are invalid. Until now, several drivers for Vista installed, although one actually worked. System Info says I'm running Vista Home Premiun X86-based PC, but the sticker on the laptop says Athlon 64 X2 dual-core (Acer Aspire 4530). Any fixes?