If you don't want anybody to see your profile on your computer you can lock it with the password. In this lesson I will show you how you can set different password options to log in, in Windows 8.
If you can't copy files that are bigger than 2 or 4 GB, usually HD movies and such, on to your USB key, it's usually due to the file system the USB key is formatted to.
Windows 8 also brings a very transparent tool for examining global indices, where you can also optionally keep track of the value of individual shares.