Comment Re:Hammer to kill a swarm of flies (Score 1) 226
It is not stupid by any means, the system stores information all over the place. It would be to hard to try and encrypt each one by itself. It is far easier to just encrypt the whole thing. You would be surprised how little of a hit you take in performance. I used TrueCrypt for a good while and I never notices any slow down at all. Encryption like AES are extremely fast.
System encryption provides the highest level of security and privacy, because all files, including any temporary files that Windows and applications create on the system partition (typically, without your knowledge or consent), hibernation files, swap files, etc., are always permanently encrypted (even when power supply is suddenly interrupted). Windows also records large amounts of potentially sensitive data, such as the names and locations of files you open, applications you run, etc. All such log files and registry entries are always permanently encrypted too.