I use Karen's replicator to back to my extrenal hd. click here
You need to go to documenst and settings (your user name) and copy the folders to your external drive (desktop, internet temp files). I am not sure where the password files would be located perhaps someone else may be able to advise on that - I never save my passwords on system.
Click Start > All Programs > Accessories > system Tools > Files and Settings Transfer Wizard and follow the on screen prompts, depending on what you have installed this could take some time and quite a bit of HD space, if you have an external backup drive use it.
It may also be wise to export all your IE favourites, cookies etc, click File > Import and Export and run the wizard, you can also do the same for email contacts in Outlook Express or Outlook.
Bit of a belt and braces approach but probably worth it just in case.