http://stuarthalliday.com/how-to/maintain-your-computer-part-2/
Once your computer is looking clean, the drives have been check for possible errors you now need to do another small chore which hits virtually every computer user – Defragmentation.
This isn’t some strange form of personality disorder but a task that needs to be done to stop your Windows computer slowing to a standstill.
Here’s what it’s all about.
Whenever you or your computer creates a file (for example a photograph, song or movie), it doesn’t just scan the drive and look for a bit of free space big enough to hold it like a human would. It finds the first tiny bit of free space on the drive and breaks apart the file and put the broken off piece in there. It then looks for the next free space and repeats the process until your file is created. The fact that it may now be scattered into hundreds or thousands of tiny pieces on the drive is neither here or there. The computer is just happy it’s put the file on the drive for you. This is called file fragmentation.
Of course in order for you to look at or play this file it needs to recover these bits, reassemble them and present them to you. This takes time and the more the file is fragmented, the longer it takes. I’ve seen a single file broken into 15,000 pieces I kid you not!
Now imagine that this is happening with most of the files on your computer and this includes the ones your operating system makes everyday and you can see how it really slows the computer down and your stress levels go through the roof as you wonder what has happened to your once so-called fast computer!
Happily Microsoft provide a tool to reverse this process. Quite why it’s not automatically done for you is a mystery best known to Microsoft. But this program, called a de-fragmentation tool, will chug away putting your files back together again and so the computer magically speeds up.
In this article I tell you how to run this program.
There are several ways to do this task. You can run the built-in tool in Windows Vista and Windows 7, you can buy a tool off a company to do it for you automatically or you can get hold of a free tool and do it yourself.
The tool supplied for free by Microsoft is adequate, does the job. But it is slow and dumb. The tools you can buy will automate the process for you, doing it in the background so you’re not aware of it and will even move often accessed files about on your drive so the computer can find them faster.
Lastly there are free tools available if you know where to look. They may not be a slick as the commercial ones but they do get the job done and hey they don’t cost you anything.
I’ll describe the three options in more detail and leave the choice to you.
1. The built-in defragmenter tool.
This tool is built into Windows 7. (If you’ve got Windows XP, see Microsoft’s page on the subject. If you’re running Windows Vista, see this article on performing it) It’s made by Microsoft but it’s pretty basic and is just designed to do its job description. As defragmentation can take time, even hours if the drive is getting full and hasn’t been done recently, it would have been nice if this tool could be put to one side and let you carry on with using the computer whilst it does its job without hogging all the power. But it can’t. It can also only do one drive at a time and it’s quite mute about what it’s up to. Still, hey it’s free and safe to use (as long as you’ve performed part one of my article to check your drive for errors).
To run this tool you need to click on the Start button, bottom left of your screen.
Then at the bottom of your Start Menu that popped up, you’ll see a Search programs and files box. Type in there Disk defrag and at the top of the Start Menu will appear a list of the tools.
Click on the one called Disk defragmenter and you’ll see a tool open looking like this:
You see the two options at the bottom marked Analyze disk and Defragment disk, well clicking on Analyze disk first will get the computer to check the level of fragmentation and it displays the result in percentages next to the drive letter. If you get ~10% or over then it’s worth performing the Defragment disk option next.
If you click on Defragment disk, it performs an analysis first in any case and then you can just leave it to run or stop it at any time. It usually performs three passes before giving up if it can’t reduce the level of fragmentation. Usually this only happens if your drive is too full. This tool really prefers your drive to have 25% free on it to perform well.
Lastly you see in this window that it can be scheduled to run when you’re away from your computer. I don’t know about you, but I don’t keep my computer on at 1 AM in the morning! So pick a time, say over lunch or dinner that you know you’ll be away from it and let it perform this essential task at least once a week.
Then your computer will stay pretty nippy! 
2. Run a free defragment tool.
Why go to the bother of this when you have one built-in? Well earlier versions of Windows don’t have a one you can schedule amazingly enough and it’s slow in operation and the one you do have isn’t exactly very forth coming about what it is up to and has no tweaks to help optimise the hard drive better.
There are lots of free defragment tools around and some right dodgy ones too. But I use a decent, well thought of program that is 100% free, well respected and trusted in IT land.
It’s called JKDefrag and the version I prefer to use is JKdefrag Portable. This lovely version doesn’t need to be installed, it just lives in a folder and this can be on any disk or USB stick if you like. So it’s really easy to use and remove if you don’t want it any more.
- JKDefrag Portable. More information on it here at Wikipedia.
For people wanting a version with more meat on it, then I suggest you give MyDefrag a look at (it’s based on JKdefrag). It’s a bit more like the ‘Swiss Army Knife’ of free defragment tools.
You get a nice looking picture of the state of your drive when it’s running and you can see at a glance how messy your drive is or not.
Screen shot of JKDefrag Portable.
In this picture, the black represents 'free space', green as files/programs and yellow as important Windows files.
What I like about using either of these tools is that you can close the program at any time or get it to run through all your drives without you having to be present to action it.
So no need to buy a commercial product unless you’re running a business and want the support that comes with that purchase. In that case I can thoroughly recommend O & O Defrag Professional made by a well respected German IT company.
- O & O Defrag Professional. More information on it at Wikipedia.
They even offer a free trial version for you to test run.