after clone by ghost, program run slower

I recently use Ghost ver8 to clone a netware 3.12 from a 2g hard drive to 40g hard drive with identical ghost.
Although I only use 2g of that 40g hard drive,it is accepatable.
but the customer complain, the program they usually use( a accounting program) is slower than before in the new hard drive.
Does anyone know the reason and have a solution to improve the speed?
If I want to increase the volume space without changing any content,how can I do?
What ‘s the difference between ghost and ghost for netware?
I really appreciate, if anyone can help me?