After installing Windows 7, I was browsing around and found that they had removed the little "shared" icon overlay to let users know that a folder is being shared.
I found a way to list the shared folders and noticed that my computer was sharing a bunch of folders that I didn't want shared. Most importantly, ALL my personal and system files were exposed by default. WTF!?
You can disable them by running "Computer Management" through "compmgmt.msc" and selecting "Shared Folders" > "Shares".
There you can find a list of all shared folders in your computer.
Unfortunately, all your drives and system folders are shared by default because the "Server" service is an absolute cunt. Unsharing them will do nothing, because when the service is restarted, the disabled shares will appear again.