Article ID: Q100005

The information in this article applies to:

• Direct I/O, version 4.2

SUMMARY

During installation of Direct I/O on systems running Windows 2000 or Windows XP with a system memory of 128 MB or less a system crash could happen.

MORE INFORMATION

In an attempt to make the above mentioned Operating Systems safer and more robust against effects caused by poor written drivers Microsoft decided to protect portions of the kernel mode memory by setting their attributes to ReadOnly. The motivation behind this was to prohibit any inadvertent or intentional modification of code or data regions which have not been meant to be modified.

Unfortunately this really wise intention has not been  thought through completely. Instead only blocking any harmful attempt it actually brings down the system. Furthermore not each system can be protected equally, because the mechanism heavily depends on implementation details of the processor and the configuration of the Operating System.

To correct a bug in the kernel (see Q700001) Direct I/O has to patch the kernel upon start. This causes the crash.

Up to now there seems to be a rule that any system with a system memory of more than 128 MB will not use Memory Protection and therefore is not affected by this issue. Systems with 128 MB or less usually have the Memory Protection feature activated.

RESOLUTION

Download the most recent version of Direct I/O. Then run the setup program again.

STATUS

Ingenieurbuero Paule has confirmed this to be a bug in the products listed at the beginning of this article. This problem was first corrected in Direct I/O version 4.2.241.