Download and install TweakUI:
Microsoft PowerToys for Windows XP (TweakUI)
Annoyances.org - Download TweakUI
After installing, go to Start > Programs > PowerToys for Windows XP >
TweakUI. Expand "Logon" and uncheck "Show unread mail on Welcome screen".
Note: Unread message alerts may indicate you have unread messages not only
in Outlook Express, but Hotmail and/or MSN email accounts as well.
or
If you just want to remove it for one user:
1. Log into the XP box with the user you want to change
2. Click Start and click Run
3. In the runbox type regedit and press ENTER
4. Navigate to the following key:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\UnreadMail
5. Double-click on the dword
MessageExpiryDays in the right column. If the dword is not there, create it.
6. Set the value to
0
If you want to remove the notification for all users:
1. Click Start -> run -> regedit (as noted above)
2. Navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\UnreadMail
3. Double-click on the dword
MessageExpiryDays in the right column. If the dword is not there, create it.
4. Set the value to
0