Open Control Panel>Power Options and look for the bit where it says " change when the computer sleeps" set that to never,then do the same for "choose when to turn off the display".
Hi Sonak,on my vista PC the icon for power options is a green battery with a power lead coiled around it,do you have an icon like that in your Control Panel folder?
Ah,must be slightly different because yours is a laptop and mine is a desktop,I just assumed to control panel would be the same layout.Sorry.Glad you have it sorted now :-)