Restrict users in AD from accessing files and Folders created by other AD users?

Hi,

 In my office we have AD with Server 2008 R2 version and AD members are using Windows 7.

 My question is how can we restrict users in AD from accessing files and Folders created by other AD users.

For Ex: If a user creates a folder/file in D drive of windows 7 then another user cannot access that folder/file.

Regards

Faisal

regards, Faisal