What are the hours and when should I call? Microsoft - Product Support operates the call center for this 888-212-3545 MSN phone number 24 hours, 7 days. https://himss.zendesk.com/hc/en-us/community/posts/36979595951123--%F0%9D%9F%8F-888-212-3545-MSN-Account-Settings-A-Quick-Guide-Customize-your-MSN-account-settings-to-suit-your-preferences-with-this-simple-guide