ms wireless comfort keyboard 4000 --- volume control problem

OS -- Win XP Pro, always kept fully patched and up to date. 3 Gigs of RAM.
Intel Pentium D, Gateway system [GX7022e].

MS Wireless Comfort Keyboard 4000

Just bought this keyboard. I am generally pleased with it. But. The
volume up/down keys are nonfunctional. The mute works fine [including
onscreen display of mute state]. I installed from the included CD -- but
the volume keys were not working. I then went online [to MS] and downloaded
and installed the latest drivers [moving up from 6.30.xx to 6.31.222.01]. I
have searched the internet, and it appears that my problem is not unknown --
but nothing I have found provides a solution.

The keyboard it replaced was a PS/2 Gateway unit that came with the machine.
That keyboard worked without any problems [including its volume controls].
I have neither upgraded nor changed anything else on the machine since
installing the MS keyboard and wireless mouse [an MS Wireless Laser Mouse
5000] -- so I am reasonably certain this problem is purely coming from the
new keyboard and/or drivers. I've checked all software volume controls I
use, and they continue to work OK.

I'd much appreciate any help with this glitch. I'd hate to have to go back
to the Gateway keyboard just to get back the convenience of keyboard volume
controls. True, it's a quite decent keyboard, it's just not what I was
looking forward to using, and it is not as comfortable as the MS keyboard.

I had the same issue. I finally tracked down a post somewhere that said to check the HID Input Service, which was the issue in my case. Once I turned it on, the volume controls worked. Hope that helps.

After a ridiculous amount of hunting and pecking, I came across this MS workaround. Adding registry changes to all the "ControlSet" lines is the trick.
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Here's the link: http://support.microsoft.com/kb/932875
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*In Windows XP, click Start, click Run, type regedit in the Open box, and then click OK.
2. Locate and then click the following registry key: HKEY_LOCAL_MACHINE/System
3. Expand System.
4. Expand ControlSet001.
5. Expand Services, and then click HidServ.
6. In the right pane, right-click Type, and then click Modify.
7. In the Value data box, make sure that the value is set to 20, and then click OK.
8. Expand HidServ, and then click Parameters.

Note If the Parameters registry key does not exist, follow these steps:
1. Click HidServ.
2. On the Edit menu, point to New, and then click Key.
3. Type Parameters, and then press ENTER.
9. In the right pane, right-click ServiceDll, and then click Modify.

Note If the ServiceDll registry value does not exist, follow these steps:
1. Click Parameters.
2. On the Edit menu, point to New, and then click Expandable String Value.
3. Type ServiceDll, and then press ENTER.
10. In the Value data box, verify that the value is set to %SystemRoot%\System32\hidserv.dll. If the value is not %SystemRoot%\System32\hidserv.dll, type %SystemRoot%\System32\hidserv.dll in the Value data box, and then click OK.
11. Repeat steps 5 through 10 for each registry key that contains "ControlSet" in the key name. For example, if there is a registry key that is named CurrentControlSet or ControlSet002, click CurrentControlSet or click ControlSet002. Then, repeat steps 5 through 10.
12. Exit Registry Editor, and then restart the computer.
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Repeating steps 5 through on each "ControlSet" is what is missing in other instructions to solve this problem.

Have fun! Hope this helps somebody.