DOCUMENT:Q163852 08-AUG-2001 [crossnet] TITLE :Invalid Operand with Locked CMPXCHG8B Instruction PRODUCT :Windows for Workgroups and Windows NT Networking Issues PROD/VER:WINDOWS:95; winnt:3.5,3.51,4.0 OPER/SYS: KEYWORDS:kbhw kbWinNT400sp4fix kbHardware ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 - Microsoft Windows 95 - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== When an Intel processor receives a specific invalid instruction, your computer may stop responding (hang). Your computer must be turned off and restarted to return to normal operation. NOTE: Although there is no known operating system or application that issues such an invalid instruction, you should be aware that a program can be written maliciously to contain such an instruction. The operating system would not trap this error, as it should, which results in the processor hang. CAUSE ===== This problem can occur due to an error in the following Intel processors: - Pentium processor - Pentium processor with MMX technology - Pentium OverDrive processor - Pentium OverDrive processors with MMX technology NOTE: This problem cannot occur on the following Intel processors: - Pentium Pro processor - Pentium II processor - i486 and earlier processors This problem is known as "Invalid Operand with Locked CMPXCHG8B Instruction" and is erratum 81 on the Pentium processor errata list. For more information, please contact Intel or go to the following Intel web site: http://support.intel.com/sites/support/ RESOLUTION ========== Intel has identified a workaround to this problem that allows the operating system to trap the invalid instruction and not pass it to the processor. Microsoft has worked closely with Intel to provide the following hotfixes: Windows NT 4.0 -------------- To resolve this problem, obtain the latest service pack for Windows NT 4.0 or 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 For your convenience, the English version of this post-SP3 hotfix has been posted to the following Internet location. However, Microsoft recommends that you install Windows NT 4.0 Service Pack 4 to correct this problem. ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/hotfixes-postSP3/pent-fix/ Windows NT 3.51 --------------- To resolve this problem for Windows NT 3.51, obtain the following fix. This fix should have the following time stamp: 11/24/97 12:42p 49,840 Hal.dll 11/24/97 12:42p 48,768 Hal486c.dll 11/24/97 12:42p 65,648 Halapic.dll 11/24/97 12:42p 46,704 Halast.dll 11/24/97 12:42p 81,056 Halcbus.dll 11/24/97 12:42p 79,200 Halcbusm.dll 11/24/97 12:42p 46,912 Halmca.dll 11/24/97 12:42p 67,696 Halmps.dll 11/24/97 12:42p 40,480 Haloli.dll 11/24/97 12:42p 53,744 Halsp.dll 11/24/97 12:42p 49,840 Halws3.dll 11/24/97 12:42p 41,072 Halwyse7.dll 11/21/97 01:35p 821,904 Ntkrnlmp.exe 11/21/97 01:34p 810,016 Ntoskrnl.exe This hotfix has been posted to the following Internet location: ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT351/hotfixes-postSP5/pent-fix/ Windows 95 ---------- A fix for Windows 95 is not yet available. STATUS ====== Windows NT 4.0 -------------- Intel has confirmed this to be a problem in the Intel processors listed above. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4. Windows NT 3.51 --------------- Intel has confirmed this to be a problem in the Intel processors listed above. A supported fix is now available from Microsoft, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information. Windows 95 ---------- Intel has confirmed this to be a problem in the Intel processors listed above. Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available. Additional query words: 95 3.50 3.51 4.00 i386 malicious hangs freeze freezes erratum cmpxchg8b compare and exchange 8 bytes cold boot hard ====================================================================== Keywords : kbhw kbWinNT400sp4fix kbHardware Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbNTTermServ400 kbNTTermServSearch kbWinNTS351search kbWinNTS350search kbWin95search kbZNotKeyword3 Version : WINDOWS:95; winnt:3.5,3.51,4.0 Hardware : x86 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.