If you have a CPU that is running at 1Ghz or faster then there is an update you need to check out
Note:This is only for those who have Windows 98/ME. It is not needed for Windows NT/2000.
Basically, Your computer can now shutdown/turn off the power before your hard drive has finished writing all of its data. This is BAD! It means small things like every time you start your computer it says 'Windows was not shutdown correctly' or it just gets more and more strange errors. So, to combat this problem Microsoft has a released a fix to make the computer wait until the Hard disk is finished writing before turning off the power.
With the advent of CPU's running 1Ghz and beyond, things get done ALOT quicker than they did a few years ago. This also means that your computer can shutdown even quicker. No more waiting a few minutes while waiting for Windows to shutdown. Your computer can shutdown in a matter of seconds if not quicker.
There is just one problem with this. As soon as Windows is done it tells the computer to turn the power off. OK, Great even, now we don't have to push the power button. Its just one more step saved, right? Well, yes. But, Windows speed processes up by delaying certain actions that don't have to happen right now. It even queues/stacks things up and hands them off so it can go do other things. Like, writing to the hard disk. Have you ever been sitting at your computer, reading something on the screen and all of a sudden the hard drive light starts flashing? Well, Windows decided it wasn't do anything important waiting for you and decided to do some clean up of resources. This includes writing anything to the hard disk that hadn't been done already. Now, Windows isn't the only thing in your computer that does this. Almost everything in your computer does this. It actually makes your system work much faster.
Now, why is this a concern for those running at 1Ghz or faster? Because your hard disk does the same thing. It gathers all the data its going to write in big chunks. But, it can't write as fast as your computer can give it stuff to write. So it has cache (pronounced 'cash') which is sort of like an 'inbox' for stuff to do. So Windows can throw stuff into the cache/inbox and say 'OK, that is done' and move on to what's next. So, Windows finishes tidying up everything and tells the system to turn off. Unfortunately, your computer is thousands of times faster that your hard disk. The power is turned off and the hard drive still may have stuff in the cache/inbox, and once the power is off everything in the cache is 'forgotten'. This is why your computer my keep coming up and telling you it didn't shutdown properly even though it looks like it did. Or even worse, it slowly corrupts itself without telling you and your system slowly degrades everytime you turn it off.