Could someone please tell me how to remove the room-tone hiss from a
voice recording done via microphone into a computer sound card?

I am trying to record the narration for a flash movie. I am using a
Labtec Axis-521 headset microphone.I am recording the voice over using
RealOne Player Plus. I have a SoundMAX Digital Audio card and software
on my Dell.

Is this inferior hardware and software for voice recording or do I
have roomtone hiss because I don't have filtering software?

Thanks,
Fred