Thanks Jeff

The time out is on inserts.But i can not test any thing on main server.I even could not run DBCC SHOWCONTIG ('dbo.Table_Name' ) to see if it is necessary to rebuild the indexes.

(it takes a lot of time and causes many time out)

Is there any other way to find the hot index?

What do you mean by partitioning?Do you mean using partitioning with an appropriate range of data in that table to separate the files?