If I remember right for win98,
ops: run "msconfig" (through "start-run"), see if there is any mention of the SLD in the startup program list there, if so uncheck or untick the box for the prog. Also look in the .ini and .bat file there for entries, probably not there but better to check.
You can also run "regedit", (again through start-run), do a search in regedit for SLD, and remove the keys that are found (carefull not to remove any sld from another program).
Last resort is to search for everything with SLD in it, and remove it by hand.
Restart after making changes.
http://netsquirrel.com/msconfig/