>> either Tablet PC or XP Embedded <<

That _is_ confusing and I think you should demand clarification...

There is an "XP Tablet PC" os and "Vista Tablet PC" but, the "Embedded"
sounds like Windows CE.

From your description of the job, if the screen size of a pocketpc is
sufficient for the engineers to record results (i.e. a scrolling 2.25"
screen) think pocketpc will be the lower cost, more robust and easier
handled solution... i.e. it's a hell of a lot easier to input on a
pocketpc while standing than most tablets.

>> 1) Can I run a VB program on the Tablet PC edition of Windows and/or
XP Embedded?, <<

Yes on XP Tablet and PocketPC, but not sure if vista supports VB

>> 2) Can these OS's be used to connect the tablets to a domain for
uploading the results? <<

Yes, assuming the above conclusions

>> 3) Which is the better OS for accepting a hand written signature
from a user (a bit like signing for a parcel from a courier)? <<

The question should be "how much is it going to cost for a custom
application with the capability of obtaining and storing an image of the
signature" While both Tablet and PocketPC (windows CE) can obtain
images, handling the image after it is generated is the task.

>> 4) Is there a version of either of these OS's that can be installed
on a Virtual PC for testing purposes? <<

The PocketPC os has an emulator... may need visual studio to run it.

afaik, there is no "tablet" emulator since any Windows computer
duplicates the tablet functionality except for the pen input.

Beverly Howard [Microsoft MVP-Mobile Devices]