try this it does take a while to do.
Connect your TomTom to your computer
via USB and open up your Windows
Explorer and go to the drive. (It will be listed as TOMTOM (E) or some
other drive letter).
Copy the Yellow Folders one by one to your PC. Ideally, save all the folders under a new folder that you name.
You may find that the folder ttntools and gns may not be copied. This is o.k. if they aren't.
Format your Tomtom via MY Computer.
Copy the Yellow Folders from the backup
you made in STEP 1 back to the TomTom.
Open TomTom Home
Click on Upate Now.
Install the latest update onto your TomTom.
Once installed, switch your TomTom off, then disconnect if from the PC.
Thats it. From now on, make a full backup using TomTom Home prior to any updates.
Also note, that copying all the files will take some time.