Reverting to default account safely

[ImagineAll]

I'm using Windows XP Pro, and I'm the only user on my computer. I never had problems booting up automatically as "default" with full rights to change any settings. I recently made the mistake of adding "my user name" as a "limited account", which allowed me to use most of the settings I had before as "default", because I was told that I would be less vulnerable to attacks. Unfortunately upon starting the computer in the morning now, it hangs up on "starting the computer" because it seems unable to recognize either "default" or "my user name". The only way to get it to start is to click F8 upon rebooting, then click "Reboot" on the menu, which gives me a choice of starting either account. I've tried to remove "my user name" account when logged into "default", but it warns me that I will lose my settings, my bookmarks and my saved e-mails on Outlook. I don't want any other account anymore - how do I eliminate it without losing anything? Thanks for your help!