What service pack are the clients running? The agent requires SP4 as a minimum... that might be the cause.
The laptops are running Windows 2000 SP4.
Not sure what the exact differance between the laptops and the desktops.
Is there anything specific I should look at to see why it install on the Desktops vs. Laptops?
File version nunbers?
Window 2000 version numbers?
In theory they should be the same
Can you post the frminst log and the mfeagent.msi.log from a laptop and we can have a look?
if i recall correctly Agent 4.0 Patch 4 requires Windows 2000 SP4 Security Update rollup 1 to be installed