The adapter requires of drivers:
The "A2" in the name signifies the second generation of this adapter. The original PC Adapter had a history of driver conflicts and firmware issues. The A2 was designed to be the "universal" solution. It features a USB interface on one end (for the PC) and an MPI/DP port on the other (for the PLC). Simatic Pc Adapter Usb A2 Driver Windows Xp
To ensure the adapter is correctly recognized by your Windows XP system: The adapter requires of drivers: The "A2" in