Go to the Toshiba website to check for an updated driver for the sound card. If no new version is available, I would download and install a fresh copy of the same driver. Your current files could be corrupted, or it may be an hardware issue. You can always purchase an inexpensive soundblaster card and install in an empty pci slot.
I have a Toshiba M45 Series laptop. Here is a list of my sound program entries via "Sound, video and game controllers" in Device Manager:
-Legacy Audio Drivers
-Legacy Video Capture Drivers
-Media Control Devices
-Soundmax Integrated Digital Audio
When I boot up and try to use a video or audio file, I get an error message that there is no sound available (that is a paraphrase of the error message).
I have tried many things but the 1 thing that works 100% of the time to allow me to have sound is to UNINSTALL the "Soundmax Integrated Digital Audio" device and reboot. It is the only one of the list above that will allow me to uninstall it. Upon rebooting, it sees the "new" component and offers to install the software for it (which, it should be noted, reads that it is NOT authorized for XP and asks me to cancel or continue anyway......I continue anyway).
After all of this, Everything works fine. But, what a P.I.T.A. to repeat these steps each time I use my pc.
I have added WMP 11, Nero 7 Ultimate, some codecs (mainly required for Nero) and a couple of video file conversion programs in the recent future and it seems like maybe Nero may be the problem by overriding my preinstalled Soundmax system. That's my guess, anyway.
Any help would be greatly appreciated!