To use the (models: LFH-3500, LFH-3504, LFH-3508, or SMP-4000 series) on Windows 7, you need the correct drivers and dictation software. Philips has discontinued direct support for Windows 7, but legacy drivers still work.
Here’s the complete search-style content for : Philips SpeechMike Pro Drivers for Windows 7 (32-bit & 64-bit) philips speechmike pro drivers windows 7