TIA Portal V13 and later (as well as STEP 7 V5.5 SP4 and later) include the PC Adapter USB A2 drivers as part of the SIMATIC Device Drivers package. Separate driver installation from the CD or download is not required, as the drivers are already integrated. However, if you are using an older version such as STEP 7 V5.4, you must install the driver separately.
If you lack the original disk, the driver package is available for download via the Siemens Industry Online Support (SIOS) portal (Article ID: 78453460). Simatic Pc Adapter Usb A2 Driver Windows Xp