Hardware config error for s7 300

Hie,
I am beginner for s7 plc's, so in that learning process i tried hardware configuration, where i choosen right serial numbers, but it was a red slash on that io module when I go online,

So when I open the diagnostic buffer of that module it was showing a msg "module config okay but not able to find that module"

Can any suggest me the remedy for this..??

Exactly what module type numbers ?
And show us a screenshot of your HW config.