Version Information

Possible permanent solution: Upgrade to TrueCrypt 5.1 or later, decrypt the system 
partition/drive, and then re-encrypt it using a non-cascade encryption algorithm (i.e., AES, Serpent, 
or Twofish).*
Please note that this not a bug in TrueCrypt (the issue is caused by inappropriate design of the 
third-party activation software). 
*
The reason is that the TrueCrypt Boot Loader is smaller than the one used for cascades of ciphers and, therefore, there 
is enough space in the first drive track for a backup of the TrueCrypt Boot Loader. Hence, whenever the TrueCrypt Boot 
Loader is damaged, its backup copy is run automatically instead. 

---

119 
Known Issues & Limitations 
It is strongly recommended that you read also the latest online version of this chapter at: 
http://www.truecrypt.org/docs/?s=issues-and-limitations
 
Known Issues 
• (There were no confirmed issues when this document was created.)
Limitations
• [Note: This limitation does not apply to users of Windows Vista and later versions of Windows.] 
On Windows XP/2003, TrueCrypt does not support encrypting an entire system drive that 
contains extended (logical) partitions. You can encrypt an entire system drive provided that it 
contains only primary partitions. Extended (logical) partitions must not be created on any 
system drive that is partially or fully encrypted (only primary partitions may be created on it). 
Note: If you need to encrypt an entire drive containing extended partitions, you can encrypt the 
system partition and, in addition, create partition-hosted TrueCrypt volumes within any non-
system partitions on the drive. Alternatively, you may want to consider upgrading to Windows 
Vista or a later version of Windows. 
• TrueCrypt currently does not support encrypting a system drive that has been converted to a 
dynamic disk. 
• TrueCrypt volume passwords must consist only of printable ASCII characters. Other characters 
in passwords are not supported and may cause various problems (e.g., inability to mount a 
volume). 
• To work around a Windows XP issue, the TrueCrypt boot loader is always automatically 
configured for the version of the operating system under which it is installed. When the version 
of the system changes (for example, the TrueCrypt boot loader is installed when Windows 
Vista is running but it is later used to boot Windows XP) you may encounter various known and 
unknown issues (for example, on some notebooks, Windows XP may fail to display the log-on 
screen). Note that this affects multi-boot configurations, TrueCrypt Rescue Disks, and 
decoy/hidden operating systems (therefore, if the hidden system is e.g. Windows XP, the 
decoy system should be Windows XP too). 
• The ability to mount a partition that is within the key scope of system encryption without pre-
boot authentication (for example, a partition located on the encrypted system drive of another 
operating system that is not running), which can be done e.g. by selecting System > Mount 
Without Pre-Boot Authentication, is limited to primary partitions (extended/logical partitions 
cannot be mounted this way). 
• Due to a Windows 2000 issue, TrueCrypt does not support the Windows Mount Manager under 
Windows 2000. Therefore, some Windows 2000 built-in tools, such as Disk Defragmenter, do 
not work on TrueCrypt volumes. Furthermore, it is not possible to use the Mount Manager 

---

120 
services under Windows 2000, e.g., assign a mount point to a TrueCrypt volume (i.e., attach a 
TrueCrypt volume to a folder). 
• TrueCrypt does not support pre-boot authentication for operating systems installed within VHD 
files, except when booted using appropriate virtual-machine software such as Microsoft Virtual 
PC. 
• The Windows Volume Shadow Copy Service is currently supported only for partitions within the 
key scope of system encryption (e.g. a system partition encrypted by TrueCrypt, or a non-
system partition located on a system drive encrypted by TrueCrypt, mounted when the 
encrypted operating system is running). Note: For other types of volumes, the Volume Shadow 
Copy Service is not supported because the documentation for the necessary API is not 
available. 
• Windows boot settings cannot be changed from within a hidden operating system if the system 
does not boot from the partition on which it is installed. This is due to the fact that, for security 
reasons, the boot partition is mounted as read-only when the hidden system is running. To be 
able to change the boot settings, please start the decoy operating system. 
• Encrypted partitions cannot be resized except partitions on an entirely encrypted system drive 
that are resized while the encrypted operating system is running. 
• When the system partition/drive is encrypted, the system cannot be upgraded (for example, 
from Windows XP to Windows Vista) or repaired from within the pre-boot environment (using a 
Windows setup CD/DVD or the Windows pre-boot component). In such cases, the system