I'm not sure if you are running Home or Pro, so the following will apply to the Pro version. I haven't had any experience with home so I'm not sure if it has the same security features.
Go to My Computer --> Tools --> Folder Options --> View Tab --> uncheck the box "Use Simple File Sharing (Recommended)"
This will bring up the security tab for all drives, directories, and files.
Go to the drive and right click --> Properties --> Security Tab
From there you can select which users and groups have access to the particular object. Hope this helps
