The problem happens occasionally on different Windows XP versions, it seems that it does not depend on installed service packs or hardware. That problem never happens on the others Windows versions too (Windows 98, ME or 2000). It follows that the problem should be retrieved in software installed on a local machine.

Clean systems (Windows XP Home Edition, Professional Edition and Professional Corporate Edition, without any third-party drivers or software installed) bear out that it is not operating system's problem, any DOS full-screen graphical programs including Aurora Borealis work without any problems.

Solving this problem I found that Windows XP has some ACPI-functions differs from previous Windows OS versions. After those modified functions are called DOS-application still works, but it cannot get access to processor for some reason. As I found before, Windows XP doesn't block DOS-applications itself. So, it must be other software installed on a given computer, which use irregular access to motherboard or processor resources. The last step was to define software that may cause this problem. As it proved, many applications that can control motherboard resources directly may be discovered as a problem reason. Software CPU cooling programs, applications that control fans speed, or even temperature monitors - all of them are potential cause.

Here's a list of software I found that causes DOS-based applications to stop ('hang') running on Windows XP:

• S2kControl
  
• Speedfan
  
• Motherboard Monitor
  
• EasyTune (?)
  
• ...
  
• probably any other program that controls motherboard parameters, such as speed of fans, temperatures, Bus Disconnect option & software CPU cooling applications