bh99mh 0 Junior Poster in Training

My nephew has Windows 98SE together with MSN Premium 6.2. He downloaded MSN 7 which has given him problems. He is getting a message when he boots up, just before the screen freezes. The message is "Command Line Option Syntax Error. X MSN Toolbar - Type Command/? for help. He did go into DOS and tried this but got nothing. Can anyone please help. I suggested that he uninstal all of his MSN and start afresh. He did this but was still getting the message. I did ask him not to empty his 'Rubbish' so he could restore if necessary.
Many thanks
Mary (Scotland)