Aló, Claudio.

>Is there any way to run (over the LAN) an application..
>
>I mean, from a machine 'Y' i'd like to run a program into the machine 'X'..
>
>We have some 'configuration program' that needs to get the hd's serial number of all machines over the LAN..

You can do this using COM+ components running in every machine (NT, W2K, or XP Pro). But I don't think this is exactly what you want... You want some way to do it without installing anything? In this case I found it difficult.

You may try using some Remote Control software like www.Radmin.com, PC Anywhere, if you can do this interactively. If all the workstations are Win XP, you're lucky, because they all have Remote Desktop (see the WinXP help).

If nothing of that helps, tell us some more details.

Best luck,