INFO: SYMBOL Checksum Error Reported When Kernel Debugging

ID: Q184826

The information in this article applies to:

Microsoft Windows NT Workstation version 4.0 SP4
Microsoft Windows NT Server version 4.0 SP4
Microsoft Windows NT Server version 4.0, Terminal Server Edition

SUMMARY

When you are loading symbols for a kernel debug against a computer running Windows NT 4.0 Service Pack 4 (SP4), the debugger reports a checksum error, symbol mismatch, against the following components:

Win32k.sys
Ntdll.dll
Kernel32.dll
Winsrv.dll

The symbols that are being used are correct, and should not report this error.

MORE INFORMATION

This behavior is by design, assuming you are debugging a computer with a single processor.

If you install SP4 on a computer with a single processor, you smash the lock prefix instructions. This matches the behavior of Windows NT setup. This behavior is new to SP4 and did not occur with Service Pack 3, so lock prefixes were left intact even on computers with a single processor.

The lock x86 instruction only comes into play on multiprocessor computers. When SP4 is installed on a computer with a single processor, we replace the lock instruction (0xF0) with a NOOP instruction (0x90).

Additional query words: debugref


Keywords          : NT4SP4Fea ntstop 
Version           : WinNT:4.0
Platform          : winnt 
Issue type        : kbinfo

Last Reviewed: February 7, 1999