Version Information

partition/drive must be decrypted first. Note: A running operating system can be 
updated
(security patches, service packs, etc.) without any problems even when the system 
partition/drive is encrypted. 
•
System encryption is supported only on drives that are connected locally via an ATA/SCSI 
interface (note that the term ATA also refers to SATA and eSATA). 
•
When system encryption is used (this also applies to hidden operating systems), TrueCrypt 
does not support multi-boot configuration changes (for example, changes to the number of 
operating systems and their locations). Specifically, the configuration must remain the same as 
it was when the TrueCrypt Volume Creation Wizard started to prepare the process of 
encryption of the system partition/drive (or creation of a hidden operating system).
Note: The only exception is the multi-boot configuration where a running TrueCrypt-encrypted 
operating system is always located on drive #0, and it is the only operating system located on 
the drive (or there is one TrueCrypt-encrypted decoy and one TrueCrypt-encrypted hidden 
operating system and no other operating system on the drive), and the drive is connected or 
disconnected before the computer is turned on (for example, using the power switch on an 
external eSATA drive enclosure). There may be any additional operating systems (encrypted or 
unencrypted) installed on other drives connected to the computer (when drive #0 is 
disconnected, drive #1 becomes drive #0, etc.) 
•
When the notebook battery power is low, Windows may omit sending the appropriate 
messages to running applications when the computer is entering power saving mode. 
Therefore, TrueCrypt may fail to auto-dismount volumes in such cases. 
•
Preserving of any timestamp of any file (e.g. a container or keyfile) is not guaranteed to be 
reliably and securely performed (for example, due to filesystem journals, timestamps of file 

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attributes, or the operating system failing to perform it for various documented and 
undocumented reasons). Note: When you write to a file-hosted hidden volume, the timestamp 
of the container may change. This can be plausibly explained as having been caused by 
changing the (outer) volume password. Also note that TrueCrypt never preserves timestamps 
of system favorite volumes (regardless of the settings). 
•
Special software (e.g., a low-level disk editor) that writes data to a disk drive in a way that 
circumvents drivers in the driver stack of the class ‘DiskDrive’ (GUID of the class is 4D36E967-
E325-11CE-BFC1-08002BE10318) can write unencrypted data to a non-system drive hosting a 
mounted TrueCrypt volume (‘Partition0’) and to encrypted partitions/drives that are within the 
key scope of active system encryption (TrueCrypt does not encrypt such data written that way). 
Similarly, software that writes data to a disk drive circumventing drivers in the driver stack of 
the class ‘Storage Volume’ (GUID of the class is 71A27CDD-812A-11D0-BEC7-
08002BE2092F) can write unencrypted data to TrueCrypt partition-hosted volumes (even if 
they are mounted).
•
For security reasons, when a hidden operating system is running, TrueCrypt ensures that all 
local unencrypted filesystems and non-hidden TrueCrypt volumes are read-only. However, this 
does not apply to filesystems on CD/DVD-like media and on custom, atypical, or non-standard 
devices/media (for example, any devices/media whose class is other than the Windows device 
class ‘Storage Volume’ or that do not meet the requirements of this class (GUID of the class is 
71A27CDD-812A-11D0-BEC7-08002BE2092F)). 
•
Device-hosted TrueCrypt volumes located on floppy disks are not supported. Note: You can 
still create file-hosted TrueCrypt volumes on floppy disks. 
•
Further limitations are listed in the section 
Security Model
. 

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