Remove Unread Email Count from the Windows XP Login Screen
For All Users:
Go to Start and select run, in the run box type Regedit and click ok. Once Regedit has started navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\UnreadMail
Once there Create a new DWORD (Right click in right hand pane, New>DWORD) called MessageExpiryDays
Double click the DWORD MessageExpireyDays you just created and be sure the value is set to 0 (should be the default value if this is a new DWORD). If you only wish to make a change to your own user edit this registry key instead HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\UnreadMail