Hardware Reference
In-Depth Information
If you are using Windows 95 or Windows 98, you may receive the following
error message:
This program has performed an illegal operation and will be shut down. If
the problem persists, contact the program vendor.
If you subsequently click on Details, you may receive an error message of the
form:
[Program] caused an invalid page fault in module at [location].
This type of error is 'unrecoverable' and hence, after you click OK, the program
somewhat unhelpfully shuts down!
Note that if you are using Windows ME (Millennium Edition), you will
receive an error message of the form:
[Program] has caused an error in [address]. [Program] will now close.
If you continue to experience this type of error message you should restart
the computer. To view the details of the problem you should press ALT+D, or
open the Faultlog.txt file in the Windows folder.
To resolve this problem it is important to identify when, and in what situation,
the error message
first
occurred. Also, determine if you recently made changes
to the computer, for example, if you installed software or changed the hard-
ware configuration. In either case, you should use a clean boot troubleshooting
procedure (see later) to help you identify the cause of the error message.
General protection faults
All protection violations that do not cause another exception result in a
general
protection fault
(GPF). These can be caused by:
•
Exceeding the segment limit when using the CS, DS, ES, FS, or GS segments.
This is a very common problem in programs and it is usually caused when a
program miscalculates how much memory is required in an allocation.
•
Transferring execution to a segment that is not executable (e.g., jumping to
a location that contains garbage).
•
Writing to a read-only area or to a Code segment.
•
Loading a bad value into a Segment Register.
•
Using a null pointer. A value of zero (i.e. 0) is defined as a null pointer. When
operating in Protected Mode, it is always invalid to use a Segment Register
that contains zero.
A
general protection fault
often indicates that there is a problem with the
software that you are using or that you need to update a device driver installed
on the PC. The Dr. Watson utility (see page 410) can often help you to identify
the cause of the error message by taking a snapshot of the system at the point
at which the fault occurs.
