How can I get my TomTom GO 510 working again?

I attempted to do an update on my TomTom but it came up with an error message saying that I needed to update my HOME. I did this and tried the updates again, to no avail as it now said that Ihave no space on my device and should remove some items. Before doing this I thought I would do a backup, an error message came up telling me I have nothing to back up.
I went into manage my device and it showed me that I had plenty on my device so I removed some items. the problem is now that I have nothing what so ever on my TomTom so it is unuseable. I still have back ups etc in My Documents. Please any ideas?