Best way is built-in BitLocker encryption which is transparent to Amazing Charts. Available on Server 2008/2008R2/2011/2012/etc. and Windows 7 ULTIMATE (not Pro), Windows 8 Pro, Win Vista Ultimate (Not Business), and the Enterprise versions.
Try to use a TPM module if possible. It's pretty light on resources too. They finally added it to the pro versions of the latest Windows iteration (Windows 8).
Bear in mind, that drive encryption only protects against physical theft.