Question:Why is my computer running so slow?
Answer:Fragmentation of the hard drive.
Fragmentation occurs when you create and delete files. Windows keeps a list of where all the 'free' space on the hard drive is and each time you create a file, Windows removes space used by that file from the 'free' space list. Each time you delete a file Windows adds the space occupied by that file to the end of the of the 'free' space list.
The position of these 'free' space fragments can be anywhere on the hard drive, so, for example, if you were to delete twenty 1kb files and then create a single 20kb file, windows would take those twenty 1kb chunks from the 'free' space list and allocate them to the 20kb file.
When you come to read this file the computer has to find the chunks of free space, due to the random nature of the allocation of these chunks, the first could be at the beginning of the hard drive the next one could be at the end of the hard drive and the one after that could be in the middle, and so on...
As the action of moving the hard drive head is the slowest task your computer performs there is a delay each time your computer moves the head to a new location. Therefore the more fragments there are the slower your machine gets.
The defragmentation program on your computer takes all the bits of files and assembles them in one location, thus significantly reducing the number of times the hard drive head has to be moved, therefore making reading files faster.
The defragmentation program
You get to it by clicking Start / Programs / Accessories / System Tools and expand (click on the outward pointing arrow) and select Disk Defragmenter. Once selected a dialog box appears if you have configured the defragmenter to start minimised, it gives you the choice of which drive to defragment, usually C or any removable drive if you happen to have an external hard drive that would benefit from defragging.
If you've had your computer for a year or more and it has never been defragged, the first defrag will take a very long time. I suggest running defrag at night, in the morning it should be finished depending on the size of your hard disc.
To defragment drive C, click on the defragment button and leave the program alone it takes a while and a pop-up box alerts you when the job is done.
Also in the System Tools section you will see Disc Cleanup, this handy little tool goes through your computer scanning all the files that can be safely got rid of or compressed to save on hard disc space, if you have a small hard disc this is a tool you should use regularly just to squeeze every last ounce of performance out of your machine.