Atrue novice seeking help!!!!!!

I hope some one here can help me.
I purchased a Packard Bell PDA with TOMTOM on it. Got the GPS receiver and tried it out today on the car. All i can say is why did i not do this ages ago. Its brilliant i think!!!
Anyway i only have a 128mb card so i know i am restricted as to how much i can have on the PDA, however the uk map worked, YES WORKED great until i decided to reload the softeare again because i thought tha it was short of info due to lack of knowledge regarding certain streets in Reading. For some reason i have now lost info. When i tap navigator, it tells me no maps found.
So i decided to install GB map from disk.
Now i too get a message saying in needs a number but it does let me continue without it. The problem is that whenit starts to transfer files(Icon with folder going from left to wright) it gets about a third of the way and then computer freezes. Some one tell me i am being stupid and put me on the righht track please. Regarding number i dont seem to have one. I got this on ebay with disks and user manuals but no numbers

[Charlie]

Welcome to our forums.
If I were you I would contact the seller as you should have an Activation code with the software. You will need this to go any further with the system.