From Canon:
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Details
Firmware Version 2.0.7 incorporates the following functional improvements and fixes:
Firmware Version 2.0.7 is for cameras with Firmware Version 2.0.3 or earlier. If your camera's firmware is already Version 2.0.7, it is not necessary to update the firmware.
The firmware update takes approximately seven minutes.
Notes:
Once the EOS-1D X camera is updated to Version 2.0.7, it cannot be restored to a previous firmware version (Versions 1.0.2 through 2.0.3).
Once the EOS-1D X camera is updated to firmware Version 2.0.7 from previous firmware version (Versions 1.0.2 through 1.2.4 and 2.0.3), it is recommended that the latest application software *1 be used. Certain previous versions of this application software do not support functions which are added by the new firmware.
You can download the latest application software from our Web site.
*1: EOS Utility version 2.14.10a or later (Supported OSes: Windows 8/ 7 / 7 SP1 / VistaSP2 / XP SP3, Mac OS X v10.9 / 10.8 / 10.7 / 10.6)
*1: Digital Photo Professional version 3.14.46 or later (Supported OSes: Windows 8 / 7 / 7 SP1 / Vista SP2 / XP SP3, Mac OS X v10.6 / 10.7/ 10.8/ 10.9)
The instruction manual has been revised to accommodate the improvements and fixes provided as of firmware Version 2.0.3 or later.
Support
Download Firmware Version 2.0.7 for the EOS 1DX.
Download the latest instruction manual from our Website.
Download the latest application software from our Website.
This information is for residents of the United States and Puerto Rico only. If you do not reside in the USA or Puerto Rico, please contact the Canon Customer Support Center in your region.
Thank you,
Customer Support Operations
Canon U.S.A., Inc