No version of Logger Pro is compatible with a 64-bit version of Windows XP.
Windows Vista 64-bit support started with Logger Pro 3.7 for the LabPro. Full support for all hardware that works with Logger Pro, including Ocean Optics Spectrometers and TI graphing calculators, was available in version 3.8.3. Windows Vista support (both 32-bit and 64-bit) ended with Logger Pro 3.8.7.
The current version of Logger Pro supports all hardware equally on both 32-bit and 64-bit versions of Windows 7, 8, and 8.1. The current version of Logger Pro 3 is available at http://www.vernier.com/tech/lpupdates.html