All other audio DISABLED ???? help

Using Windows 7
I just downloaded the latest version of Audacity to use with an older Ion USB turntable. All seemed to go well with recording.
I wanted to save/export it in MP3 format, so downloaded the recommended LAME converter. Seemed to work ok up to this point.
When I went to play the MP3, it loaded OK in WMP, and track time was progressing, but i could not hear anything.
I then exported it in WAV format to see if the converter was bad. Still could not here it.
I saved both WAV and MP3 to thumb drive, and they both played OK on another W7 PC.
I can play the same track when in Audacity program itself only
Then I noticed when trying to watch some other videos i have on my computer(WMV’s) or online videos, I there was no audio.
It seems Audacity has disabled ALL other audio from playing on my PC.
Can anyone suggest what I can do (other than uninstalling Audacity) to get any other audio working again.
Thank you in advance for any help you can provide

It’s not Audacity disabling the audio, it’s how Windows handles USB audio devices. See here for how to fix: http://manual.audacityteam.org/man/FAQ:Playback#usb

Steve.
Thanks Much for the reply.
I actually found that same solution just before seeing your reply, only I went the long way around - via control panel, hardware, sound etc… and found the default set to USB Audio.
Thanks Again