You were possibly hacked. I've read about (and one time it happened to me) being hacked as an ftp server. They take over part of your drive and the directories are usually very nested and each folder has a period in front of it. My suggestion, install/run 1-2 antivirus and 2-3 anti-spyware a few times and scan the drives like crazy. I typically run norton antivirus, spybot, ad-aware & MS's free antispyware app. Norton costs, the others are free.