MSN page open automatically while opening IE

HI 

we have win-2008 r2 as Dc
group policy set for all clients to open default homepages -http://myportal.domain.co.in,http://capital.domain.co.in

when we open iE from client system three pages are coming (msn page,http://myportal.domain.co.in,http://capital.domain.co.in)
but we set two pages only, automatically msn page coming,
i cant understand why msn page popup while open IE

Please can anyone help me

Regards

Surendhar.J