Category: <b>shells/command interpreters</b>
<br>Flags: Undocumented function<p>
<pre><b>INT 2F - DOS 3.0+ CRITICAL ERROR HANDLER - INSTALLATION CHECK</b>

	AX = 0500h
Return: AL = status
	    00h not installed, OK to install
	    01h not installed, can't install
	    FFh installed
	BX destroyed (MSCDEX v2.21-2.25)
	CF clear (MSCDEX v2.21-2.25)
Desc:	determine whether a critical error message override is installed
Note:	this set of functions allows a user program to partially or completely
	  override the default critical error handler's message in COMMAND.COM
SeeAlso: AH=05h,INT 24
</pre>