Possibly. It sounds like you may not understand how efs works. Efs encrypts
files not folders or hard drives. You need to export the efs certificates
and store them in a safe place. Practice using them in different scenarios
until you are sure you know the procedure. You need to be able to decrypt a
file on a computer that is not in the same domain (if applicable) and has
never been used to decrypt files from the original computer before. Once you
can do this successfully you will be relatively safe from losing your data.
Efs wasn't really designed for your scenario. I would recommend a different
method of encrypting the backup. Personally I would recommend an unencrypted
backup stored in a secure place under lock and key. The last thing you need
when restoring a backup is complications.
