Q137539 General Causes of STOP 0x0000007F Errors.

Symptoms

You may receive get the error on Windows:

”STOP 0x0000007F (UNEXPECTED_KERNEL_MODE_TRAP) “

Cause

This can arise if the either of following circumstances arise:

>Computer has hardware/software issues
>Computer's processor speed has been altered (e.g. processor is set at 150 MHz running at 187 MHz).

The STOP error above is due to a trap having occurred in kernel mode. The most common causes of ‘STOP 0x7F’ are:

>Low-level hardware corruption (corrupt memory)
>Mismatched memory modules
>Faulty motherboard

To determine an approximate cause, examine the parameters at the top of the STOP screen:

**STOP 0x0000007F (0x000000XX, 0x00000000, 0x00000000, 0x00000000)
UNEXPECTED_KERNEL_MODE_TRAP

The most important parameter is the first (0x0000000X) which can contain various different values. This occurs depending on the value of the parameter. Traps that cause a ‘STOP 0x7F’ are found in the Intel x86 microprocessor manual.

Here are some of the most common ones:

Values Meaning
---------- --------------------
0x00000000 Divide by Zero Error
0x00000004 Overflow
0x00000005 Bounds Check Fault
0x00000006 Invalid Opcode
0x00000008 Double Fault

Resolution

Use the appropriate method to resolve this error:

• If any software/hardware causes a certain trap then a debug can determine the cause. To troubleshoot hardware problems you can try the following:

1. Test your RAM by running diagnostic software. Replace any RAM which is diagnosed as faulty or malfunctioning. Also ensure the RAM is the right speed.

2. Swap or remove controllers, cards etc.

3. Change the motherboard.

4. If over clocking the processor speed reset it to the default speed.

5. Check for any updated hardware drivers or BIOS updates for your hardware.

For more info on processor errors you will need to consult the Intel processor manual.