Hello. 
I'm running Sonar Home Studio 6 on Windows Vista (yeah, I know, but it usually behaves ok)...
I have been recording audio through the PC's line-in, as I have done for years; suddenly today
I can no longer playback recorded audio --- I can SEE that it has recorded, and when I Export
as a WAV file, that file plays fine (through Windows Media Player on the same PC).  But when
I try to simply play the audio within Sonar, it is silent.  The counter moves -- it LOOKS as if it's
playing -- but no sound.  Just 2-3 days ago it played back fine.
I tried restarting the program, then restarting the entire system; I've tried several different
Cakewalk files, all of which worked fine last time I used them, and NONE of them will play back.
I would appreciate any insight.
Thanks so much.
Jeff

is the master buss is output to your soundcard?

As far as I can see, every output is set to my soundcard: "Realtek High Definition" -- allthough
I'm no expert, and I see many different places to choose "output"; I have played around with 
all of them, in every conceivable combination, and still no sound.

And the audio engine stays enabled?

What drivers do you use for you soundcard (MME, asio4all or something like that)? Did you do any upgrades / updates lately (Win, AV, etc.)? 
Best of luck.

Thanks for your responses.
The Audio Engine appears to always be running.
The Driver Mode is "MME (32-Bit)". It's the only mode that works with my sound card.
Windows has done its automatic updates recently, I'm sure, but I can't think of any other system changes.

What soundcard do you have? Is it an internal one, or external?

I take it you are using the onboard audio for Sonar.  Just for the heck of it you might try Asio4all.  Download it and install it then change your audio drivers in Sonar to asio.

My apologies for the delayed response...
Thanks again, everyone, for your help.
Zargg71 -- my sound card is internal: "Realtek HD"
MFanning -- I may just try that. Thanks.