There is no fixed yes or no answer to this question. In fact, if it worked
on someone else's XP system, it still might not work on the bosses system.
The only way to ensure such compatibility is to dual boot XP with a previous
operating system which you know is compatible with the application. In this
way you can ensure functionality of mission critical applications that you
are not at this time ready to replace.
While XP retains some DOS code, the Command Prompt included with XP is a DOS
emulator and not true DOS. Even some old DOS commands might not work or be
accepted with the Command Prompt. XP also has a compatibility mode that can
be tried as well but if you are looking for guarantees, there are none. You
are talking about a legacy application that pre-dates a fully updated XP by
around 10 years and was not designed for XP.
As I said, if it's mission critical, you can dual boot with a previous OS
with which you know the application is compatible. Your boss should
understand, this situation is only going to get worse. Even if it will run
with XP, he may find some functions not working as expected and as the
system is updated or we move to the next operating system, the likelihood of
incompatibility increases. He's living on borrowed time and should be
looking for a replacement.
