I am going to explain my story just incase it helps someone else... ok... when I turned on my Nokia N800... the opening white Nokia screen just stalled for 2 minutes until it would reboot itself... so I had to take out the battery to turn it off... tried again... same thing... I couldn't get past this... so... I go to reinstall the software BUT Nokia says it has a "newer version" of the Installation Software Update Wizard (Version 1.1.4) so I update it... rebooted Windows PC... so then I try to connect my Nokia N800 to my Windowns PC it cannot do it... tried for 2 hours (taking out battery everytime) and no connection... then after 2 hours the opening white Nokia screen gets streaked with black lines... ok at this point I made plans to go buy another Nokia N800 in the morning... BUT... I get a final thought... maybe I will uninstall the "newer version" and reinstall the older Installation Software Update Wizard (1.1.3)... it connected... reinstsalled software... everything works perfectly again... I have no idea what happened... but DO NOT UPDATE THE "Installation Software Update Wizard (Version 1.1.4)"... if you do so then make sure you have a backup of the older version! What a f#@$@#$ stessful night I had over this BS.

I had a problem similar (if not the same) to yours. Basically, after months of trouble-free use, my N800 did not go past the Nokia logo screen with the white background and the progress meter at the bottom. While the progress meter was going forward, it restarted and again started the process, which basically had the same ending, which was another restart. This kept happening until I managed to turn
off the device completely, which also was not an easy task.

I thought their was something wrong with the battery, so I went out and purchased a new one. However, even with a new battery installed, the situation remained the same. So I returned the recently purchased battery and got a refund minus a 20% restocking fee (cheapskates, they are), and sent the device, it's contents, and packaging to the online retailer I purchased it from. They received it and agreed to exchange it for a new unit, so I haven't truly incurred any monetary losses.

However, I am still interested to know how that problem arised in the first place. Would you have any ideas.

Oh there are so much info on this. Personally I think it was the WEATHER program I installed on it but do a search for "3 second reboot" on here and you will find many threads. I was lucky I fixed mine by flashing it cuz I don't have it under warranty.

Mine was under warranty, but the warranty was not valid outside of the United States.

They oughta list the computer requirements on the packaging of the Nokia N800 Internet Tablet as it seems like it needs a computer for a lot of things.

Also, people who aren't familiar with Linux (like myself) can have some challenges.

I had read and remembered this thread when I had to flash my system today because of a complex messup. I found that I could in fact use the new update software, despite what it says above. When I "switched on" the N800 by pushing the power button (holding down the home key as the instructions told me to do), I had the same problems as described in the top message in this thread.

Then I noticed that I was holding down the power key and releasing it and the home key at the same instant when I saw the USB connected symbol. When I made sure to release the power key FIRST and in a distinct operation, THEN release the home key, everything worked fine. This was somewhat tricky. It's all in the wrist!

I find flashing not as piece-of-cake as it should be, though I've had plenty of practice flashing my system, as I like to live dangerously.

To sum up, I found that the sentence "DO NOT UPDATE THE "Installation Software Update Wizard (Version 1.1.4)" in the top message above was incorrect.