Windows XP's logon screen lists the number of unread email messages associated with the user account. The message count is taken from all email accounts checked within the last 3 days using Outlook Express, Outlook, Messenger (Hotmail/MSN), and the MSN browser client. This includes not only your accounts, but those of anyone who used your computer to check their email.
The unread message count is stored in the registry at HKEY_CURRENT_USER\Software\Microsoft\Windows\Current\Version\UnreadMail and each account ever checked from this computer in the count is listed as subkeys under this key. Their unread count is only included in the total shown on the logon screen if they were checked within the last 3 days.
You can disable this feature by editing a value called MessageExpiryDays, setting it to 0. If you use any other number, it will display the number of unread messages for that many days. The default is 3.
If the value does not exist under HKEY_CURRENT_USER\Software\Microsoft\Windows\Current\Version\UnreadMail, you'll need to create a DWORD named MessageExpiryDays. By default, the value will be 0 unless you change it to another number.
If you don't want to edit the registry, you can download a registry file then double click to run it. If your web browser adds .txt to the filename, remove .txt from the file name and then double click to run it.
The next time you log on, the screen will not display your unread message count.
If there are multiple user accounts on the computer, you'll need to do this for each user who doesn't want their unread mail count displayed.
Published May 13, 2011. Last updated on August 27, 2014.