I have a Creative Sound Blaster Audigy 2 ZS Platinum Pro. I have 4 Gigs of RAM and my OS only detects 2.93 GB of RAM, so I installed 64 Bit Windows XP Professional and installed the drivers within Microsoft Updates. I opened up Sound Recorder and its not picking up any audio signal! I even tried using other recording software and still it does not capture anything. I then installed the drivers from Creative and still the same thing is going on.
Take a look at my video:
http://www.fernando4.com/nihal/jnfwebdata/videos/Sound%20Issue.wmv
Oh, and just to let you know, Vista 64 Bit does not have this issue, but the audio capibilites are cr ap, so is the 32 bit version.