searching for a hp omnibook xe4100
 

In working condition please. Hard drive not essential though.

Paul, if It is just for the use of the serial port, you can take an image of the existing hard drive and restore it onto any laptop these days and keep programs etc intact, that will widen your scope for looking for a replacement.
Have a looksie at Acronis true image with universal restore. I have it and it works fantastic, when a pc dies with a lot of software still on its usable hard drive, I take a backup of it with acronis and restore it onto the new pc and it just works, install a couple of new hardware drivers and off it goes.I have restored pc images to laptops and vice versa.