This error message can occur if either of the following
conditions exists:
- Your computer has hardware or software problems (hardware
failure is the most common cause).
- You try to over clock the speed of your computer's
processor (for example, you set a 150 MhZ processor to run at 187
MhZ).
The above STOP error means a trap occurred in kernel mode and
the trap is either one the kernel is not allowed to have or is always fatal.
The most common causes of a STOP 0x7F are:
- Low-level hardware corruption, such as corrupt memory
(RAM)
- Mismatched memory modules
- A malfunctioning 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 one (0x0000000X) which
may have several different values. The cause of this trap can vary, depending
on the value of this parameter. All traps that cause a STOP 0x7F can be found
in any Intel x86 microprocessor reference manual as they are specific to the
x86 platform. 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
Divide by zero error
A divide by zero is caused when a DIV instruction is executed and
the divisor is 0. Memory corruption (or other hardware problems) or software
failures can cause this.
Overflow
The overflow instruction occurs when the processor executes a
call to an interrupt handler when the overflow (OF) flag is set.
Bounds check fault
This fault is generated when the processor, while executing a
BOUND instruction, finds the operand exceeds the specified limits. A BOUND
instruction is used to ensure that a signed array index is within a certain
range.
Invalid opcode
This fault is generated when the processor attempts to execute an
invalid instruction. This is generally caused when the instruction pointer has
become corrupted and is pointing to the wrong location. The most common cause
of this is hardware memory corruption.
Double fault
A double fault occurs when an exception occurs while trying to
call the handler for a prior exception. Normally, the two exceptions can be
handled serially, however there are several exceptions that cannot be handled
serially and in this situation the processor signals a double fault. The two
primary causes for this are hardware and kernel stack overflows. Hardware
problems are usually related to CPU, RAM, or bus. Kernel stack overflows are
almost always caused by faulty kernel-mode drivers.