Your ID is OK. The Outlook Express Inbox is the problem.

The Inbox is probably corrupt. Move all messages to a local folder you
create and then delete the Inbox as follows.

Tools | Options | Maintenance | Store Folder will reveal the location of
your Outlook Express files. Write the location down and navigate to it in
Windows Explorer or, copy and paste it into Start | Run.

In WinXP, Win2K & Win2K3, the OE user files (DBX and WAB) are by default
marked as hidden. To view these files in Windows Explorer, you must enable
Show Hidden Files and Folders under Start | Control Panel | Folder Options
Icon | View, or in Windows Explorer | Tools | Folder Options | View.

With OE closed, find the Inbox.dbx and delete it.  A new Inbox will be
created automatically when you open OE.

General precautions for Outlook Express:

Do not archive mail in default OE folders. They will eventually become
corrupt. Create your own user defined folders for storing mail and move your
mail to them. Empty Deleted Items folder regularly. Keep user created
folders under 100MB, and Default folders as empty as is feasible.

After you are done, follow up by compacting your folders manually while
working *offline* and do it often.

Click on Outlook Express at the top of the folder tree so no folders are
open. Then: File | Work Offline (or double click Working Online in the
Status Bar). File | Folder | Compact all folders. Don't touch anything until
the compacting is completed.

Turn off e-mail scanning in your anti-virus program. It is a redundant layer
of protection that eats up CPUs and causes a multitude of problems such as
time-outs and account setting changes. Your up-to-date A/V program will
continue to protect you sufficiently. For more, see:
http://www.oehelp.com/OETips.aspx#3

In Tools | Options | Maintenance: Uncheck Compact messages in background and
leave it unchecked. {N/A if running XP/SP2}.

And backup often.

Outlook Express Quick Backup (OEQB):
http://www.oehelp.com/OEBackup/Default.aspx

~~~~~~~~~~~~

For the next time you reformat, see these, especially cloning.

Backup & Restore:

http://www.insideoe.com/backup/

http://www.oehelp.com/backup.aspx

Backing up and Cloning your OE Identities:
http://www.insideoe.com/backup/clone.htm

If you are transferring to another PC, and have access to a Windows XP setup
CD, or if both computers are running Windows XP, see:
http://www.microsoft.com/windows/IE/community/columns/OEtopten.mspx#EBAA

Backing Up OE And Moving To Windows Mail:
http://www.oehelp.com/backup.aspx

If you move to a new identity, you don't need to import any Hotmail
messages/folders from the old identity.  OE only displays what's on the
MSN/Hotmail servers.

Tip: IE (yes, IE) Tools | Internet Options | Privacy | Sites | type in

   live.com [and]
   hotmail.com [and]
   msn.com

then Allow cookies for each domain, in turn.