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STOP 0x00000001, 0x00000001 (Parameter 1, Parameter 2, Parameter 3, Parameter 4) APC_INDEX_MISMATCH

Parameter 1 - The address of the system function or system call
Parameter 2 - value of Thread -> ApcStateIndex computations
Parameter 3 - value of the Thread -> KernelApcDisable
Parameter 4 - The value of the previous KernelApcDisable

Applicable to the following Windows Vista configurations: Home Basic, Home Premium, Ultimate, Business, Enterprise, Starter, Home Basic N, Business N, Business 64-bit Edition, Home Basic 64-bit Edition and Business N 64-bit Edition.

This STOP error can occur during startup or at other times. The 8 digit hexadecimal number 0x00000001 translates to the error APC_INDEX_MISMATCH which may be caused by the following:

1. A kernel-level application or device driver running in kernel mode created a mismatch of thread and asynchronous procedure calls (APC) indexes. This is probably due to a file system mismatch in the number of processes that entered the critical area compared to those that left. Allowing the software to run at this point will corrupt or damage the system.

2. This could be due to newly added hardware or software issues.

3. This error can pop up when a CD or DVD is inserted into the drive

4. This error also happens when the computer uses the Windows Vista Aero color scheme.

5. Sometimes, when we unlock the computer and login to the default desktop this STOP error shows up.

6. This STOP error sometimes occurs after the computer transitions into to sleep mode repeatedly (by customer usage).

7. This problem can also happen in a secure desktop environment (when we lock the computer) where an application has registered an "event hook" using an Application Programming Interface

8. Problems in the Windows system file win32k.sys can trigger this STOP error.

9. Memory corruption can also create these conditions.

10. Too much RAM (> 2GB) may exceed motherboard and BIOS capabilities and create this STOP Error.


  1. Verify that all your hardware is compatible with the Vista operating system.
  2. Verify that all the software updates are installed for the current Operating system as well as on all device drivers and external third party software on the system.
  3. If this error showed up when the computer was restarting, go to Step 8. If the computer was operating normally when this error occurred, then continue to Step 4.
  4. Check the "Problem Reports and Solutions" page or VISTA. Click on Start->Control Panel->System and Maintenance->Problem Reports and Solutions. This facility searches online for device driver updates and solutions to problems caused by external hardware or software.
  5. If the error appears during restart (and the restart is successful in spite of the error) , set the Windows Memory Diagnostic to get more details about the problems during restart. Then go to Step 8.

    a. Click on Start->All Programs->Accessories. Right-click on Command-Prompt and choose "Run as administrator"
    b. Enter mdshed.exe at the command prompt. Schedule the tool to run at the next restart.

  6. Run the Memory Diagnostics Tool on Vista to see if the memory is corrupted. This is a very useful application that can detect memory errors during restarts. To configure this tool:

    a. Close all applications.
    b. Click on the Start button and in the Search field, type "Memory Diagnostics Tool".
    c. Choose what type of tests you want to run from the options provided.
    d. Choose the cache setting for each test and the pass count ( number of times to repeat each test)
    e. Set it to run immediately and follow the prompts. Computer restarts.
    f. If the tool finds memory errors, it reports it immediately.

  7. Try to restore the system to a previous restore point. Click on the Windows Start button and type "System Restore" into the Search field. The System Restore application comes up. Choose a restore point and continue to restore system.
  8. Try to restart the computer again. If you cannot restart it using the mouse or keyboard options, shut down the computer by pressing down the manual Power button for a few seconds. When the computer has completely shut down, press the button again to restart the computer.
  9. As the computer restarts, press and hold the F8 key before the Windows Logo appears.
  10. Use the arrow keys to select "Repair the computer" in the "Advanced Boot Options" menu.
  11. Choose a keyboard layout and login using username and password. You will need administrator password if it is set on the system. If you have never set it, then just click on "Continue".
  12. Choose Startup Repair from the menu for "System Recovery Options". The Startup Repair process will try to repair the computer.
  13. If this does not solve the problem, check the CD-ROM driver and try to install another one. Open up the chassis and check the motherboard. Reseat the memory chips. Check the power supply. If you have testing equipment for the hardware, use them to detect any hardware malfunctions
  14. If none of the above works, you may have to reformat the drive and re-install the operating system.


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