DOCUMENT:Q241589 11-DEC-2001 [winnt] TITLE :Kernel Access Fault in Windows Terminal Server PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 SP4 OPER/SYS: KEYWORDS:kbtool ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 SP4, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== Sessions to Terminal Server users may disappear on retail builds of Windows NT 4.0, Terminal Server Edition (sessions that are not connected to a Windows NT debugger session). CAUSE ===== The way certain programs paint the screen can cause the Remote Desktop Protocol (RDP) to use an uninitialized variable and bugcheck the server. This problem aggravates a path in SDGSendSDARect, which has an uninitialized variable for one rare path (bitmaps with a height of 1 and a width greater than or equal to 12). This uninitialized variable can affect later invocations of the function by causing a problem with a compression estimate that uses certain assumptions. When this problem occurs (a kernel access fault,) an error message appears. It is seen in the form of a disappearing session to a user on retail builds of Windows NT 4.0, Terminal Server Edition (that are not connected to a Windows NT debugger session). RESOLUTION ========== To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base: Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack STATUS ====== Microsoft has confirmed this to be a problem in the Microsoft products that are listed at the beginning of this article. Additional query words: ====================================================================== Keywords : kbtool Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400sp4 kbNTTermServSearch Version : winnt:4.0 SP4 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.