Hello...
This problem just happened on an XP machine that has been working fine for years - until just now.

Machine:
DIY, AMD Athlon 2.01, 2GB, Asus M2N-SLI MB, WinXP-2, GeForce 7600GT video, 250GB HD, on board HD audio.

I installed an M-Audio Delta 2496 audio board to support a ham radio panadapter. All was working fine. Normal sound through computer speakers/headset. The panadapter display had a small artifact, and I started chasing that down. I deleted/installed the M-Audio driver several times. I did the same with the SoundMAX software/drivers just in case they were involved. Then the problem began...

Problem:
With M-Audio board removed and drivers deleted, I cannot get SoundMAX to function. In the Control Panel sound applet, the Audio/Voice tabs show a greyed out "No Playback Devices." This is the same regardless of how many times I delete/reinstall SoundMAX, reboot the computer, etc. However, there is a SoundMAX icon in Control Panel. When the icon is clicked, a "small" SoundMAX panel appears that cannot be expanded to show the program's various sound controls/etc. On this small panel there is a wizard to test sound to the speakers. It works: noise comes out of the speakers. That's it. Nothing more. Other programs that have a sound output all throw an error saying some VERSION of "no sound capability."

I reloaded XP just in case: nothing. Device Manager says that the HD sound with SoundMAX is operating properly. I've checked out the MB bios parameters, and nothing has changed. Several months ago I wiped the HD and reinstalled XP and all programs, everything. Clean machine has been working great up to this point. I'm stumped.

Sure hope someone has some insight on this one so that I don't have to wipe the HD and reinstall everything. Thanks.

...robertGood evening Niky828 and welcome to CH

Did you try going to Asus web site and download the latest audio drivers for XP? for the motherboard.

Please keep in mind when updating drivers that the current one (sound drivers) should be removed first then if asked reboot and then install the new one you just download and install it.

Yes even if the drivers are corrupt you can still see the icon in the systray in the corner by the clock.

Sometimes soundmax drivers can be finicky    Unfortunately, new/different/old drivers make no difference. I even spent $40 on a "driver updater" that was so-so at best. Besides, I have installed the same drivers any number of times to GOOD effect. The problem persists. This is a problem at the operating system level; some SORT of "switch," perhaps in the registry, has been set wrong. Any other ideas? Thanks.

...robert
The problem you may have is within the hidden devices view on your device manager. See this link. Make sure to create a restore point first. The COMMAND set devmgr_show_nonpresent_devices=1 is explained here. Good luck.Jason...

Bingo! A bit sketchy at first, but followed the instructions on the first link, and got everything BACK to normal. Many thanks. You saved me a lot of cash and heartache. Best to you.

...robertThanks for coming back also and sharing the solution worked for you.