The personal data security is a very important matter, so lets see how protect own data/privacy within free software solutions.
WinGuard Pro free and premium versions available, for various Windows versions, Vista included.
Free Hide Folder for all Windows versions
My Lockbox as above, also supports 64 bit
fSekrit specific to encrypt text notes, for all Windows versions
SafeHouse Explorer for Windows XP, Vista, Server, 32 or 64 bit; available also for U3 devices!
You can also read The 5 Best TrueCrypt Alternative Services you can use to encrypt your data, especially if you use cloud storage services.