Hi Songbird.
What is the version of W7.........Home, Premium, Pro or Ultimate?
Which version of WinAmp are you using.....have you tried reinstalling it?
Re: the " no sound at all" you mention.......................
Is there a Speaker Icon in Task Bar bottom right of screen and does it have a Red X or any red marking on it at all? If answer is yes, then either the sound driver is missing or things not set up correctly in Control Panel/Hardware and Sound
Have you looked into Device Manager to see if there is a Yellow triangle with an exlamation mark in it anywhere,,,,,,,,,,,,,,,,,,,,,,,,look at the entry for "Sound, video and game controllers"......if there is a yellow triangle then you have a driver issue.missing or corrupt.
Finally, have you run/installed Windows updates yet? I found that Windows 7 has to download and instal the drivers for sound to play. The Driver can be in the Important or Optional updates
WinAmp can be a PITA. I don't use it now, haven't done so for over a year, but I do recall having a problem similar to yours when I used it.