Q: Contacts disappeared from MS Outlook

Hello nsiotto,

Thanks for using the Apple Support Communities!

I understand that you are no longer seeing your contacts in Outlook on your Windows computer. To begin troubleshooting, I would suggest adjusting your view settings in Outlook, as the following article suggests, to try to find these contacts. 

Look for missing data

Depending on your view settings, you might not see all of your calendar events and contacts in Outlook. If you don't see them all, search for them in Outlook. If needed, adjust your view settings so that all contacts and events show up.

If you can't sync contacts and calendars using iTunes for Windows - Apple Support

Cheers!