Well, almost.
Windows XP does allow the 1747-PIC/AIC+ driver to run, but only under two important conditions:
1. The serial port must be built-in. No USB or PCMCIA or Ethernet converters to RS-232 will work.
2. RSLinx must run as an Application. Use the RSLinx Classic Launch Control Panel (Start -> Programs -> Rockwell Software-> RSLinx) to switch between the default Service mode and Application mode.
Even with these two conditions satisfied, some PC's still cannot run the 1747-PIC driver because of power-saving or other hardware issues. That's why the USB to DH485 interface called the 1747-UIC was developed.