I found a internal speaker driver for win98:
http://support.microsoft.com/?kbid=138857

but it doesn't seem to work on my pc! Altough I don't get an error
under the system-hardware-cofiguration, when I go to the property
settings, the test-button is disabled. Booting into DOS is the only
way so far I can heer the beep on the internal speakers! There should
be some assembler (debug) code to do this, but what?