I bought the new maps from website, and can not install

Download TomTom Home. Follow th link below for this purpose.
http://us.support.tomtom.com/cgi-bin/tomtom_us.cfg/php/enduser/std_adp.php?p_faqid=5122&p_created=1150044449&p_sid=7XHxWOZj&prod_lvl1=&prod_lvl2=&cat_lvl1=&p_accessibility=&p_redirect=&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD0yNDIsMjQyJnBfcHJvZHM9JnBfY2F0cz0mcF9wdj0mcF9jdj0mcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9mbmwmcF9wYWdlPTE*&p_li=&p_topview=1
Select your operating system (XP, Vista) on the link above.
Then click download. Once downloaded Install.
Once installation is complete, Reboot your computer.
Open tomtom home by clicking the icon on the taskbar.
Connect the USB cable to the GPS. Switch on the GPS. Connect the other end of the USB cable to the computer.
Wait for a few minutes for the GPS to go through the self check procedures.
You have a fair chance that a new map will download. Follow on screen instructions. If this does not work, Try clicking on tools (in the tomtom home software). Click on latest map guarantee.
If your free guaranteed map feature was expired, you may have to buy a new map unless you have a backup copy of the map. If you have one, just copy the map folder to the root directory on the GPS. You will see the GPS harddisk as you see a CD or DVD on your computer file manager.
If you do not have a backup, and if by chance a friend of yours have a TomTom, connect that device to a computer and copy just the map folder (It will be named USA_Canada_and_Mexico_p for example). It is pretty big folder with approximately 1.6 GB of data. Copy this folder to your GPS. This should fix your problem as a last resort.

Connect the GPS to the computer. Forget the Tom Tom home for a little while. Use the windows explorer or file manager. Check whether the TomTom is shown as a drive. If yes, Right click on it. Then click properties. Check how much is the used space and how much is the free space. If you see that there is only about 50MB free space, that could be the reason. Tomtom update do not seem to overwrite the map file. Now check the properties of the new map file. It may be approximately around 1.3 GB to 1.5 GB. Since I do not have a Europe map I do not have the correct size. If the new map size is anything bigger than the available space on your GPS drive, then the update will not complete and crash. Solution. Copy the existing map (North American map has a name something like USA_Canada_and_Mexico_P) folder to your computer. Once you have a secure copy, delete this map folder from your GPS drive. You will now see that you have approximately 1.7GB of free space. copy the map folder from your CD to your GPS drive. Once copying is complete, safely remove the GPS from USB port. Restart and try it out on a known route to check efficiency.

Thanks returned item to store Happy New Year to you all and thanks once again Ian Dempster

To update maps you should run Tom Tom home on your computer and then connect the GPS

It will then ask you if you want to connect to the computer and you would tell your GPS yes.

Tom Tom home will once it finds your GPS then proceed to do any minor updates.

If your map is out of date it will offer you the option of purchasing a newer version.

don't be tempted to look for free / pirate maps !
These can cause problems in starting up your GPS (believe me)

Tom Tom map prices are not too bad and compared to many GPS are quite easy to install using Tom Tom home.

If you don't have Tom Tom home the latest version can be found here.

when your registered it with tom tom they take note of your maps
check your online tom tom account and it should let you re-download your maps.

I you backed it up to your computer you can also restore the maps from there with the tomtom home software

You were able to successfully download windows files with your Mac and transfer them to your Tom Tom? I'd suggest trying the transaction again, but doing it with a windows machine. (Trust me, I have a Mac and I realize how unwell it likes to play with Windows.) {But I wouldn't trade it}

Yes, it can be replaced, the map cartridge is a standard SD memory card.
These can be bought quite cheap in most camera/computer stores or in several department stores.
They can also be bought online from amazon See Here $6.65
Once you have the new card, connect the device to your computer. Open the TomTom Home application. Click on 'Update My Device'. This should then install the application onto the SD card. Alternativly, you could perform all the steps above without the SD card in the device, this will install the application onto the internal memory. Note: you may also need to install your maps, voices, etc after you update. 

Move old map from device to computer, then update with new map...

If you haven't got Tom Tom HOME 2.5 then go to this web page and download and install it.

http://www.tomtom.com/services/service.php?id=16&tab=87

Run Tom Tom HOME with the Tom Tom connected (say YES to connection) and follow instructions on the PC screen to get new maps.
Peter

I suddenly lost the GPS signal today and could not get it back. All I got was the "No valid GPS signal". My solution was to tap on the GPS satellite bars when in the route map. this brought up the "Status summary page of the TOMTOM.

I then again tapped the satellite bar which brought up the "GPS Status" page. I then tapped the bar labeled "configure".

The radio button next to the option titled "Minutes (dm.m') was selected. I then moved the selection to "Degrees (d.d) and it started working.

I had just downloaded the GPS fix 5 days ago so it is not like this suddenly caused it to stop working.

This may not work for everyone but this is what it took to get mine working.

Cheers