(New) About how to Delete All SIM contacts in Microsoft Smartphone
The next time you sync, the contacts on the server will be synced back down
to your device. There is no need to delete the contacts from your SIM until
you are sure you have the contacts on your phone. Just to make sure I
reccomend you use SIM Manager to move all of your contacts back to the phone
and then sync. You might have a few duplicate entries but you will not
loose any.