The normal why to create a primary contact in MSCRM is to add the contact to the account and then go back to the account and lookup the contact that you just added. You can simplify this a bit by filtering the lookup on primary contact for only contacts from the account (see: Filter Primary Contact for contact associated to Account in MSCRM.) If you use One Click Activity this process is as simple as clicking ‘Set Primary Contact’.
Set Primary Contact from the contact form(use this for new and existing contacts).
This is simple just create a contact, preferable from the account using One Click Activity create contact related to selected entry button. Make sure the contact has a parent account; save the contact (do not close the form). Then once the contact is saved click the One Click Activity ‘Set Primary Contact’ button and you will be prompted to set this contact as the primary for the account. If there is no parent account nothing happens. Note if the account is open you will need to refresh it (F5) to see the changes.
Set Primary Contact from the contact grid (use this for existing contacts).
This is simple just select a contact in the grid (main, associate or advance find). Click the One Click Activity ‘Set Primary Contact’ button and you will be prompted to set this contact as the primary for the account. If there is no parent account nothing happens. Note if the account is open you will need to refresh it (F5) to see the changes.