Security ... think about it!
The disadvantage to this approach is that sensitive data can accidentally be stored outside the encrypted area. However, using a partially encrypted drive is better than no encryption at all. The other important thing to remember is that once you encrypt your data you CANNOT access it without the password. If you lose or forget that password, then you might as well consider that data lost. So be responsible with your password.
At least once a month, it seems some vendor or techie claims to have broken a version of a hard drive full-disk encryption (FDE) program scheme, whether it's from Microsoft (my full-time employer), BitLocker, open source favorite TrueCrypt, or some other variant. All the stories and the hype are enough to make one wonder if FDE is dead. The brief -- and slightly qualified -- answer is no. There are a handful of clever attacks, as well as software to make them easier to pull off. Luckily there are easy ways to prevent most of them. We will start, however, with an attack that doesn't have an easy defense.