I think your main resource drain is when you delete 40,000 lines:

Rows("7:40000").Select
Selection.Delete Shift:=xlUp

As a side thought you can make your code more efficient by removing the
select statements (vba doesn't need them since it isn't a user)

Rows("7:40000").Delete Shift:=xlUp

You should use this line instead:

Rows("7:40000").ClearContents

Deleting a lot of rows takes a while. Also you probably should turn
the calculation off and then on again when you are done:

Application.calculation = xlManual

code.....

Application.calculation = xlAutomatic