Q99155: Upper Memory Conflict Hangs LM During Protocol Loading

Article: Q99155
Product(s): Microsoft LAN Manager
Version(s): 
Operating System(s): 
Keyword(s): 
Last Modified: 30-JUL-2001

SYMPTOMS
========

When a workstation is cold booted (when you turn it on or reset the hardware),
LAN Manager hangs while trying to load protocols such as NetBEUI. If this does
not repeat during a warm boot (when you press CTRL+ALT+DEL), the problem may be
a conflict in upper memory.

CAUSE
=====

Cold and warm boots cause different behavior because certain network adapters,
when initialized, store memory buffers at software configurable addresses in
upper memory (640-1024 KB).

During a cold boot these buffers have not yet been configured, so EMM386 can
select their address areas for itself, causing a memory conflict when the
adapter tries to assign buffer addresses. During a warm boot, adapter memory
buffers are already configured in upper memory; EMM386 detects them and avoids
their memory areas.

RESOLUTION
==========

To verify that this is the problem, remark out EMM386: if the problem
disappears, use the x-parameter to tell EMM386 to avoid areas of upper memory
claimed by other software.

Additional query words: 2.00 2.0 2.10 2.1 2.10a 2.1a 2.20 2.2

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