Sorry… i did not realise you’re using Windows 98 and not XP.

Actually, on Windows 98 ASHWEBSV.EXE is started from: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

To manually configure your browser see the following tutorials:
For IE and permanent connection users: http://www.avast.com/files/tutorials/ws_ieproxy.htm
For IE and dial-up users: http://www.avast.com/files/tutorials/ws_ieproxy_dialup.htm
For Firefox users: http://www.avast.com/files/tutorials/ws_ffproxy.htm