I have the Tom Tom ONE (Build 2000) Tom Tom Palermo (if this Info Screen info is helpful). This Tom Tom HAS NO RESET PIN HOLE (Thanks a lot Tom Tom). I instaled included Tom Tom Home software, went to their site and downloaded New Software Version. The unit took the software procedures and then promptly went into what I can the ''stuck screen'' which is a white X in a red circle which flashes. Holding the On Button results in the Info Screen popping up and staying as long as I hold the On Button down. As soon as I release it, the unit reverts back to the flashing X. I would appreciate any help you can offer. Thanks. Tom

My thanks to the gentleman who posted the link to Tom Tom's solutions link. Although I had been there previously months ago when I first encountered this problem, there had been at that time, no instructions from them on how to properly reset the One that does not have a reset pin hole. That was in March. There are now such instructions.
The key to resetting such a Tom Tom GPS device lies in plugging your One into your computer, which automatically launches Tom Tom Home software (please remember, you have to have Home software installed on your computer already). After doing this:
1. When Home launches, go to Manage My Device Folder (p.2) and click it to open it.
2. You will see a folder-style window which lists all of the items that are your device. Select the folder tab: 'Items on device.' Then Deselect Applications. Click OK when promted. The Applications software will be deleted from your Tom Tom One.
3. IMPORTANT! Then clcik the other folder tab 'Items on computer.' Do the same here by deselcting to uninstal software on your computer as well. Click OK when promted.
4. If you do not get an automatic dialog box indicating that you need new application software installed, return to p.1 and select the folder 'Update My Device.' Follow the instructions as prompted and Tom Tom will both download new computer Home software as well as new software to the One device.
That should do it.
I will tell you that it took me three passes at this process. So it's not a breeze. But in the end it finally worked. And my One, which had been down since March is once again finally up and running with new software and as well as I remember it working.
Hope this helps others.
Tom