.NET Questions and Solutions

Symptoms
After you upgrade a Microsoft SQL Server 2000-based computer to Microsoft SQL Server 2000 Service Pack 4 (SP4), a SQL Server query that calls a registry extended stored procedure may fail, and you receive the following error message:

Access is denied.You receive the error message when you use any one of the registry extended stored procedures in the following list: xp_regreadxp_instance_regreadxp_regenumkeysxp_instance_regenumkeysxp_regenumvaluesxp_instance_regenumvaluesxp_regwritexp_instance_regwritexp_regaddmultistringxp_instance_regaddmultistringxp_regremovemultistringxp_instance_regremovemultistringxp_regdeletevaluexp_instance_regdeletevaluexp_regdeletekeyxp_instance_regdeletekey
Resolution
This problem occurs because SQL Server 2000 SP4 implements a restriction on which registry paths the registry extended stored procedures can access. When a query calls a registry extended stored procedure, the registry extended stored procedure examines the requested registry subkey against a control list of registry hives. If the registry subkey that the query requests is not in the control list, you receive the following error message:

‘Access is denied.’ This error message has nothing to do with the permissions of the SQL Server user account in the context of which one of these registry extended stored procedures is called. The error message occurs even if the user has Administrator permissions.
Note When you receive the error message, the registry extended stored procedure returns no results.

Symptoms
On a computer that is running Windows Server 2008 or Windows Vista, you receive the following Stop error message when you create a snapshot of a volume:?

STOP: 0×0000007E (parameter1, parameter2, parameter3, parameter4)
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED Notes The parameters in this error message vary, depending on the configuration of the computer.Not all “0×0000007E” Stop errors are caused by this issue.For example, you receive this Stop error message after you enable Volume Shadow Copy Service on a volume for a secondary Data Protection Manager (DPM) server.
Resolution
This issue occurs because of a race condition in the Volume Shadow Copy Service driver (Volsnap.sys).
When the volume size is being changed in the snapshot creation process, the race condition might be encountered.

Symptoms
When you attempt to shut down your computer, start Windows, or start a program in Windows, you may encounter error messages that are similar to:

A fatal exception XY has occurred at xxxx:xxxxxxxx Fatal exception errors are codes that are returned by a program in the following cases: Access to an illegal instruction has been encountered Invalid data or code has been accessed The privilege level of an operation is invalid When any of these cases occurs, the processor returns an exception to the operating system, which in turn is handled as a fatal exception error. In many cases the exception is non-recoverable and the system must either be restarted or shut down, depending upon the severity of the error.
In the sample error message that is listed above, XY represents the actual processor exception from 00 to 0F. (Note that the “h” that is listed after the 0E, 0F, and so on, in the explanations below is frequently omitted from the error message.) The xxxx:xxxxxxxx value represents the enhanced instruction pointer to the code segment; the 32-bit address is the actual address where the exception occurred.
Windows does not cause these errors, but has the exception-handling routine for that particular processor exception, which displays the error message.
NOTE: This article is primarily for informational use. Click the following link to go to the “Troubleshooting Fatal Exception Errors” section of this article:

Symptoms
This document discusses why Windows may display a “STOP 0×0000007F, 0×00000008″ error message on your computer because of a specific processor error. This error message may be displayed when a single-bit error occurs in the ESP register of a processor that is running on the computer. The article describes methods to help you troubleshoot this error.
Resolution
On a computer that is runningone or more Intel Xeon processors, or that is running other processors, Windows may display a Stop error message that is similar to the following:

STOP 0×0000007F (0×00000008, 0×00000000, 0×00000000, 0×00000000) UNEXPECTED_KERNEL_MODE_TRAP
When this problem occurs, the following conditions are true:The first parameter of the Stop error is “0×0000008″. (This error is a double-fault exception.) Because ofa single-bit error in the upper half of the ESP register, the value in the ESP register is outside the stack range of the current thread.

Symptoms
The following floating-point exception error message might occur for queries that require a “merged” histogram:

Server: Msg 3628, Level 16, State 1, Line 2 A floating point exception occurred in the user process. Current transaction is canceled.
Resolution
A float overflow exception occurs in SQL Server when it combines the histograms for two indexes to handle the cardinality estimation for outer-join operators.

Symptoms
When you attempt to shut down or restart your computer, you may receive the following error message:

A Fatal Exception 0E has occurred at 0028:C00082CD in VxD VMM(01) +000072CD
Resolution
This issue can occur if you have an incompatible or early version of a Matrox video driver installed on your computer.