When a file is saved to disk the operating system does not necessarily save it over a continuous area. If the disk is full, it might have to split the file and save it in chunks in different places. This doesn't matter to the software or the user, but it does make it slower to retrieve the file. If you think your hard disk is slower than it used to be a few months ago, you could well be right. The answer is to use a defragmentation utility that will reorganise your hard disk so that all the files are stored in continuous areas.
