DOS Application suddenly minimises to Task Bar on XP Pro

We have some legacy DOS applications which we are testing for XP compatibility.  The test PC is a Dell workstation, running XP Pro with SP2.
The problem is that the application runs for a while and then goes to a blank screen for (perhaps) 10 seconds before returning to either the XP Desktop or another open application (e.g. a Word document).  In either case, the DOS application has a minimised entry on the Task Bar, which when clicked will return to the DOS application.

The minimising can occur during input, but more often after/during the printing of a report.  The time before the application minimises in not constant (sometimes 3 hours, other times 10 minutes) and I have turned off the screensaver.

Any suggestions would be welcome!
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nikkilockeConnect With a Mentor Commented:
Hi TonyUpton711,

Are you running your DOS application full screen, or in a window?

If you are running it full screen, then probably some other window or service wants to interact with the user - which it cannot do while the DOS application is running full screen. So Windows switches the screen back to the Windows display, showing the full screen DOS task in the task bar. When you click on the icon, the DOS task is restored to full screen.

I don't think there is a lot you can do about this while running full screen, except to try not to run anything else which will want to interact with the user. It is possible that Windows Update, or your Anti-Virus program is trying to pop up one of those annoying info boxes to tell you they have done something.

Your other alternative is to run the DOS app in a window. If you play with the font size of your DOS window (click in the system box at top left, properties, font tab) you can adjust the size of the DOS window to practically fill the whole screen, so it won't look a lot different to the user. That way Windows can interact with the user without having to switch between DOS full screen mode and Windows mode.

Hope this helps,

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