Can you please do the following for me
Under Windows XP,the files will probably reside somewhere underneath "c:\documents and settings\[username]\..." where "[username]" is replaced with the account name used to log into Windows. That means that each user that logs into the machine will have a different set of Outlook Express folders.
First, let's find exactly where your mail folders are. Press the Start button, Search, For Files or Folders.... PressAll files and folders, then enter *.dbx as All or part of the filename: (Outlook Express keeps your mail in ".dbx" files). Press Search and let it go.
You'll probably find that there are .dbx files in two locations: the newer one underneath "c:\documents and settings", and another. Remember or write down that other.
To recover the mail that is in those old folders, we'll import the messages into the new location.
In Outlook Express hit the File menu, then Import, then Messages.... Select the appropriate Microsoft Outlook Express from the list of options, press Next, and Next again. At this point Outlook Express should be telling you that it thinks your messages are stored in a certain location. If that's the location of the old files we discovered above, great, but if not press the Browse button and select the directory where those old mail files are located.
Press Next and Outlook Express should import all your old messages.
please let me know if you have further difficulties
The i suggest you do a system restore.
You can do so via the following instructions
This should allow you to bring the computer back to a state before you installed your new version of outlook express.
Once done, please see if the emails are back
The easiest way is at the welcome screen press ctl+alt+delete twice and you can then log in as administrator using the password XXXXX set when you installed windows.