PC-Beeper

You need to do it with userlibs (API):

; ### Message Beep

.lib "user32.dll"
MessageBeep%(uType%):"MessageBeep"

Type parameters:

SPEAKER or DEFAULT = -1
MB_OK = 0 
MB_ICONHAND = 16
MB_ICONQUESTION = 32
MB_ICONEXCLAMATION = 48
MB_ICONASTERISK = 64

Example:
MessageBeep(128)

Or, for the classic speaker beep with variable frequency
and duration (only for NT/2000/XP), try this:

.lib "kernel32.dll"
Beep%(freq%, duration%):"Beep"

(frequency between $25 and $7fff)

(duration in millisecs)

Example:
Beep($7777, 2000)

This code was kindly provided by soja, so he deserves any credit for it.