The boot CD is Linux. It will let you "find" the F: drive and everything that's stored on the F: drive including the working copy of the image you made of the C: drive. Don't get too concerned on what type of file the image is or how Macrium does its magic. Rest assured, you will be able to see the F: drive and select the image as long as the boot CD works.
An added feature of Macrium is you don't have to worry about renaming different system images. Each image is given its own unique identifying number. That means you can store multiple images on the F: drive unlike the Windows 7 imaging tool. In Windows 7 a system image is automatically called WindowsImageBackup
. If you had that file stored on your F: drive and tried to create a new system image, you'd be warned that the original system image will be overwritten and in the end you'd still have just one system image available to choose from.
As ignatzatsonic said, try your boot CD and make sure you can follow the prompts to see your F: drive.