The Philips software and firmware drivers are 32 bit, however; they have been tested and programmed to run in 32 bit mode on 64 bit Windows Operating Systems.
The following models have been tested and will run on 64 bit Windows O/S;
Philips Digital Voice Tracers

    LFH-600
    LFH-620
    LFH-660
    LFH-860
    LFH-880

Philips Digital Pocket Memos

    LFH-9370
    LFH-9500
    LFH-9600

Verification Source: Rick Maxwell, Philips Product Manager