You can download the improved version of the GuitarFX.
Now it works ok under Windows 98 and sound card with WDM drivers.
This improved version has better distortion too.
you can download it in the file section of this yahoo group
or at: http://home.peterstar.ru/guitarfx/gfx_xp.zip
You can try New Excelent Guitar Effects Software (not mine)
http://guitar-fx.org/amp_sim5.htm
(I found the direct download link yesterday)
regards,
Mumufuk.