I asked in this ng about using 32 bit Spaceball drivers on XP64, and then decided to get an 'official' answer. I asked 3DConnexion about the availability of 64 bit drivers and got this reply: "The Windows 32-bit driver that we offer today runs fine on Win XP 64- bit. As more applications start to compile with the 64-bit library, we will evaluate support. But today, we test on the 64-bit platform with 32-bit code." I followed up by asking if that also applies to the 32 bit SolidWorks add-in, and they said: "Yes it does." Note: I specifically asked about drivers for the Spaceball 5000, which is in current production. Don't know if the answers remain true for earlier models. Art W