If the speed of your system (Vista) is very slow then try this very useful tip. There is some default setting in vista which is used to manage the write caching on disk. By default windows enabled the write caching on disk but the advanced performance setting is disabled.
Follow the guidelines:
To enable this feature, you will need to be logged into your computer with administrative rights.
First right click on My Computer icon then select the option Manage
Here small windows will appear with title Computer Management, now select the Device Manager option, then locate the SATA Disk under the Disk Drives.
Here select the enable advanced performance sittings on the SATA disk.
Now click on Ok button to apply the setting and restart your computer after any changes to go into effect.