Check your monitor power settings.
right click on your desk top then left click on 'properties' in the white box that appears.
this will bring up a 'display properties' box which should have a tab headed 'screen saver' amongst others.
select the screen saver tab.
in this tab there are 2 sections. one to select which screen saver you want to use (and what settings are applied to it), and another section which should be called 'monitor power'.
click the button here which says 'power...' to adjust your power settings.
in the next window there are 4 tabs. select the first tab (power schemes - which should be already selected by default) and you now have 4 options. leave the selected 'power scheme' in the top of the window as it is and just alter the settings for the selected power scheme.
your 4 options are: 'turn off monitor', 'turn off hard disks', 'system standby' and 'system hibernates' i would recommend setting all of these to 'never', and don't forget to click the 'apply' button after you've done this.
i would also recommend disableing hibernation in the 'hibernate' tab (this is in the same window as the power schemes tab).
once you've adjusted your power settings, don't forget to activate one of your screen savers. this is only important if you leave the monitor on for a long time with no changes taking place in terms of what is being displayed. if you leave a static image on for hours you will end up with permanent screen burn. (a ghost image that is always there - even when the monitor isn't switched on!).
i don't bother with screen savers personally as i find them annoying, and find it much easier to simply turn the monitor off whenever i'm not going to be using it for the next hour or more.
hope that solved your problem. apologies if it doesn't.
by the way, the tabs etc i described are what i have on my OS (windows XP pro) and may be named differently if you're using a different version of windows. the 'power options' settings will still be accessible via 'screen saver' tab in desktop properties though.
good luck!
