Potential data loss or system hang during system shut down

Potential data loss or system hang during system shut down

After I upgraded to a high-speed CPU and a large hard disk, my Win95 or Win ME always have corrupted data at startup? Why and how the solve it?

Problem description:

Some computers that have huge Integrated Drive Electronics (IDE) hard disk drives (e.g. over 30Gb with 2Mb cache) and newer or faster processors (e.g. over 1GHz CPUs) may have the potential for losing data. The data loss can occur if the system shuts down power to the hard disk drive BEFORE the data that is in the drive's cache is saved to the drive. This problem is not specific to any one brand of processor, computer or hardware. The problem is an industry-wide issue that affects a variety of vendors. The biggest concern with this problem is that a user may not be aware that the problem exists until after data is lost or the operating system is corrupted!

Symptoms include any of the following:

When you start up the computer, the operating system reports that the system was improperly shutdown even though it was shut down correctly.
The system does not boot to the operating system because of lost data during shutdown. The hard disk drive may sound noisy during boot up while trying to recover lost data needed to boot the operating system. The noise will go away once the operating system data is reloaded and the corrupted data is fixed. It is important to note that there is nothing wrong with the hard drive when this occurs.
The system boots up but reports corrupted data or that it cannot read data from the hard disk drive. The hard disk drive is not bad in this case, but contains data that was corrupted during the previous system shutdown. Once the corrupted data files are fixed on the hard disk drive, the system will work fine. (Again, the hard disk drive may make noise while trying to recover the lost data. The noise will go away once the data files on the hard disk drive are fixed.)

Modern IDE hard drives typically store disk writes in a hardware cache (temporary memory) and write the data to the hard disk later. “Write caching” is a performance enhancement designed to increase overall write speeds.

During shutdown, data from the cache is written to the hard disk for storage until the computer is turned on again. During a typical shutdown process, any data written just before shutdown may still reside on the hard disk's hardware cache. Older processors typically execute the shutdown code slowly enough that the hard disk's cache flushed the written data to the physical media before the machine lost power. As processors have increased in speed (now over 1GHz), the shutdown time has decreased to the point that data may still be in the hardware cache when a computer is turned off, and that data may be lost. This increased processor speed, coupled with the fact that hard drive caches have increased in size (now over 2Mb cache) further increase the chance of data loss. OS or programs using a speed-up auto shutdown procedure will make this problem more common.

This is not a problem that is specific to Windows, or any given operating system, for that matter. Nor is it specific to any one brand of processor or hardware -- it is an industry-wide issue that affects a variety of vendors. The good news for Windows 98, Second Edition (SE) and Windows Millennium Edition (Windows Me) customers is that Microsoft offers this update until the industry can address the issue. At this point, Windows 2000 is not affected by this issue, and does not require the update.

This update introduces a slight delay in the shutdown process. The delay of two seconds allows the hard drive's onboard cache to write any data to the hard drive.

Note Because the Windows IDE Hard Drive Cache Package updates your system files and requires you to restart your computer after installation, please save and close all open documents and close all programs before installing the update.

For more information on this issue, please read the Microsoft Knowledge Base (KB) Article Q273017. (This site is in English.)

Download the patch file from:

http://www.microsoft.com/Windows98/downloads/contents/wucritical/q273017/Default.asp