I cant access all my synced contacts on my computer.

I seem to have lost most of my contacts in Office Outlook 2007. They do not appear in my contacts list when I search in the contacts window. However they do appear in the icloud contacts list which is configured to mirror my Outlook 2007. these address were created in Outlook and synced to icloud. Why did they disappear from Outlook 2007. And why only some of them ?