first lets try this, since you didnt mention trying it:
Start > Run > Sndvol32
See if that works. If not,
This program will control the audio for whatever you set, however it is far from the best choice for continued use.
http://www.nirsoft.net/utils/volumouse.html might be a good option.
I spent a good hour to hour 1/2 scouring the web, and finaly found out how windows changes the volume, and its not easy or pleasant, and in fact may risk damage to your sound card by putting in to high a value. Im not sure if it is even the same in windows 98, although i think it is. Anyways, the volume controls should be located in the registry under the following key:
\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceClasses\((Realy Big Number Here))\##?#PCI#VEN_((More numbers and stuff))\#Wave\Device Parameters\Mixer\((A Number))\Controls\0.
On the rigth side you have some values like Channel 0 and Channel 1, those are the actual volumes for left and right channel for whichever pin out your viewing (Wave, Midi, Line-In, etc). The range is 0000 to FFFF. however, this is only a record of the current volume, changing these values has no effect on the current actual volume, which is likely active in memory and being edited directly through the windows api's.
thats all ive got
