So BitLocker encrypts the entire hard drive, while EFS encrypts individual files. Is there any difference in the way that they implement the encryption? Do they both use your user account password as the encryption key? Is the encryption standard they use (AES-128/256) the same?
Once you've encrypted your entire hard drive with BitLocker, does it increase security by encrypting individual, sensitive files again with EFS? Does it then doubly encrypt that file?