True Crypt is one way to encrypt the entire drive. Did I mention its Free!!!!
Bit Locker in Windows 8 Pro and above or Windows 7 Ultimate and Enterprise are another way of getting full disk encryption.
Now, as to securing traffic from PM to the clearing house, as well as with wireless transmission. That I will leave to others to answer.
Hamachi uses AES 256-bit encryption, which should meet HIPAA (128 bit) guidelines, as does LogMeIn, both Free and Pro
