If the SSD is connected a desktop PC, check if it is connected to a native SATA chipset (Intel or AMD).
These are generally numbered from 0 to 3. This ensures proper detection of the SSD by the update tool.
If this is not the case (if the SSD controller is a Marvell or Jmicron ..etc), then you must connect it to the native controller, if the detection of the SSD fails.
As for UEFI BIOS: When validating the firmware, the firmware updater tool may not recognize the SSD on some systems using UEFI. The target disk is not recognized as being valid for an update on reboot. In this case, the firmware will not be updated and you will retain the original version (For now Crucial does not offer any solution for this issue).
The Update Procedure
The downloaded firmware (Windows 7 and 8) is in the form of file. Zip (archive).
Extract and copy the update utility on your desktop and double-click the icon to launch the utility
Once the loading is complete, the pc will restart and a screen displaying the different disks that can be updated shall appear.
Once the Crucial M4 is detected, the software will request to update the latter.
Type "yes" in lowercase and confirm.
The update ends with the following message:
Current firmware is: xxx
If the operation is successful, the PC will restart