Here's what I'd look into if I were you:

Running processes:

C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\MSN Messenger\msnmsgr.exe

Various:
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O14 - IERESET.INF: START_PAGE_URL=file://C:\APPS\IE\offline\uk.htm