I came across this setting called ClearPageFileAtShutdown. The setting is described here and says:
If you are truly worried about security, boot Windows off a fully-encrypted drive. Then you needn't worry about your sensitive data being unencrypted in the paging file.
Basically, it implies that the paging file, even if it resides in an encrypted partition, is not safe--the drive must be fully encrypted for it to be safe. Why?
My understanding is that data is either stored in memory (which will be gone if no power is out regardless of whether a proper shutdown was initiated) or resides in the paging file of an encrypted Windows partition (which is obviously decrypted when system is in use but is encrypted otherwise?).
This topic is particularly important to me because I dualboot Windows and Linux and I encrypt the former with Veracrypt and the latter with dm-crypt on an SSD--the remaining space is unencrypted unallocated data (which as far as I'm concerned, is not a security issue but based on the article above, it is).
Even if you use encryption to protect sensitive data on the hard disk drive, the encryption key (and decrypted data you are accessing) would be stored in the computer's memory. Windows will automatically map out some of these data to the paging file, which remains unencrypted even when Windows shuts down.
Again, how is the paging file unencrypted when Windows is shut down if it resides in the encrypted Windows partition by default? Why is it necessary that the entire drive is fully encrypted and not just simply the Windows partition?