I am getting about 1 mbps from my Dell inspiron 640 laptop when my wife's old desktop will do it at 2.7 mbps. I have USB 2.0 ports and the external drive is 7200 rpm
Any ideas?
Thanks.

Really need to know the system specs for both, such as processor, how much memory

Ok sorry, my laptop has the Centrino Duo CPU T5300 @ 1.73GHz, 2GB RAM, 80GB hard drive (about 1/2 full) I am mainly concerned with making the transfer on this faster. The desktop has a single core CPU, 750MB of RAM, and I think a 40GB hard drive.

Your specs out match the desktop obviously

One would think laptop would be faster, is the laptop using vista?
You may have a lot more system resources being taken up by vista itself

If you do use vista, there are a couple of things to reduce resources but to honest, youi would not know any difference until you would attempt to free up resources

Here is a link with some "Tips" on speeding up PC if interested
https://www.askmehelpdesk.com/computers-beginners/frequently-ask-questions-about-computers-233870.html

Hopefully others can weigh in on the subject about the transfer speeds