If you aren't the only person using your computer (ie: you let a neighbor have access to it), you should probably be looking at getting a product that will provide you with some security. There are some freeware ones out there, and I know how we all LOVE free. I do use freeware depending on my needs, but for computer security issues, I tend to shy away from freeware but I still want something affordable. I have been using StompSoft's Digital Vault
http://www.stompsoft.com/digital-vault.html to protect my files and other important stuff so that when I let someone use my computer they won't intentionally or unintentionally see files that they aren't supposed to. I should have probably installed something like this a long time ago, especially because I work at home and have a ton of work-related stuff on my PC.