Not in Project 98 but there's really no compelling reason to delete it
anyway. It's only a snapshot of the schedule retained for comparison
purposes as you track progress and post actuals. Having the baseline there
has no effect on anything in Project's behavior or calculations, it's simply
a record of what the project looked like when you saved the baseline. If
you saved one that is no longer valid or saved it prematurely, just save a
fresh one when ready, overwriting the first one. Otherwise, if you don't
need it, just ignore it - as I said, its presence doesn't have any effect
whatsoever.