How to create private folder

in Windows 7, you can have different log ins.

or create a hidden folder

If you go the different user profiles, just remember to make the folder private either with the security tab or control panel option.

Remember even if the folder is private that way, another admin can take ownership of it(I would guess encrypting it would solve that, but I am just not worried enough to make any private folders my home PC.).

Hidden folders work well if you are not worried about someone looking for it(View -> Folder Options -> Show Hidden Folders or just 2 clicks in Win8).

To create a hidden folder:
Right click the folder to open "Properties" and mark "Hidden" in the downside of the propertied box.