If you prefer the fast way (less secure), Vista does provide an easy GUI for configure this.
Here is the what you have to call. I just wonder why they don’t provide this in normal User Account page. Then you just to select the account you want to access automatically, then uncheck this:-
It will ask you a password of the selected account. Then next time, you restart the computer, you will never have to put a password anymore 
Update before Win 7 launch (Oct 19, 2009): Although this command works with Vista and XP, it doesn’t seem to work with Windows 7. The alternative is using ‘netplwiz‘ instead of ‘control userpasswords2′ and yes, netplwiz works on Vista and XP too. Quite good, huh?
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This was not my issue until today. I just got my hand on tx2500z and as usual HP provides us tons of good & crap pieces of software. I decided to live with this configuration for a while and see how HP manages on its own image. So that I could review it as it really is out-of-the-box. However, one annoying thing I found so far was Adobe Updater from Acrobat Reader was popping up to download newer version all the time. It was quite a big file, so I could cancel it before it finished. By the way, after restarting it was still showing again and again.