Disk cleanup and defragmentation

You can use Vista's disk cleanup and defragmentation tools to remove unwanted files and to rearrange data on the disk so that files are not fragmented. Both of these actions will help increase disk access performance.
You can open the Disk Cleanup tool from the Performance Information And Tools left tasks pane or from the All Programs | Accessories | System Tools menu.
The Disk Cleanup tool allows you to select whether to clean up files from your own user profile only or the files of all users. When you select a specific drive to clean up, the tool will calculate how much space you will be able to free by running the cleanup, as shown in Figure M.

Figure M

Disk Cleanup can free up space on your disk, giving better performance.

You can access the Disk Defragmentation tool from the Advanced Tools option in the left pane of the System Information And Tools console or from the All Programs | Accessories | System Tools menu.
You can (and should) set the Disk Defragmenter to run on a regular basis, such as once per week. To avoid a performance hit, schedule the defragmenter to run at a time when you aren't normally using your computer. You can also do a manual defragmentation if you think it's necessary (for example, if you've spent the day uninstalling and installing programs, and the computer seems to be running slower). Just click the Defragment Now button, shown in Figure N.

Figure N

Defragmenting the disk regularly improves disk access performance.