tomtom one not working after backup

i have just used tomtom one home to backup for when i use the update (need to buy a bigger card first) but now it wont work when i turn it on.
it has the orange and white screen showing the sd card not inserted as with a red cross over it.
at first i thought the program had wiped it but when i open the tomtom home program it recognises it and shows what is already on there which is everyting that was there before.

i seem to have sorted it, sort of.
i deleted the contents of the tomtom one and restored the backup i had made but it seems that it then didn't have the main software on as there was more available space than there was before doing the backup. i assume that this must be that it wouldn't put back a corrupted software on if this was the problem. it maybe happened as i accidentally turned the unit off as i was backing up the first time.
anyway i then saw that there was 8.2 mb available and coincidentally that is how big the software update was but it wouldn't put it on saying there wasn't sufficient space. i deleted one of the 3 voices to free a tiny amount extra and then the software updated and flashed the tomtom one.
now...when i get the bigger sd card i have ordered, how do i put all the same info across to it, including maps etc?
would i rstore the backup i made after sorting the problem on to the new card?