I have defraggler installed and scheduled for defrags, and want to know if it's fine to disable the Windows defrag task (Task Scheduler Library->Microsoft->Windows->Defrag->ScheduledDefrag) or does Ms's defrag do anything special that defraggler doesn't already do?
Disable MS defragger.
MS defragger is not going to defrag your disk unless it is in bad shape so I doubt it will ever run.