About two out of ten times I cannot get the computer to return from standby mode. The computer tower has green lights together with the speakers illuminating, indicating that all is go, but the monitor light remains amber and the monitor remains off. Switching the monitor off and on displays the message “Going to Sleep” which it promptly does. The only way the monitor can be revived is to restart the computer. How can I resolve this problem? The computer is running Windows XP Home Edition.

Power Management is always a tricky subject, especially when particular devices do not properly return or resume from standby. Making this problem even more difficult to diagnose is that it occurs infrequently and inconsistently. As a first step, ensure that you are running the latest drivers for your video card. The problem may not be the monitor itself, but instead the video card may not be resuming from standby mode resulting in no signal being sent to the monitor (making it seem like the monitor is the problem). Visit the website for the manufacturer of your video card to download and install the latest drivers. Once this has been completed, restart the computer to check whether the problem persists.

Should the problem continue, it may also be caused by other outdated drivers on the computer. The most likely suspect is the chipset drivers. The computer chipset acts as the middleman between all the computer components and handles communications between the computer processor (CPU) and other subsystems within the computer. If the drivers for the chipset are not up-to-date, this could be hampering the required communication between different components, resulting in problems when attempting to resume the computer from standby. Therefore, you should also visit the website for the manufacturer of your computer motherboard to determine whether there are any updates which may resolve the issue.

Another possible explanation for this problem is a conflict between the power management settings within Windows and the computer BIOS. The computer BIOS stands for the basic input output system. As the name implies, this provides the basic code for the computer to boot and recognise devices (such as hard drives, video cards, keyboard, and mouse) before passing control to the computer operating system (in the case of your computer, Windows XP). Many computer BIOSes have settings for power management, and these low-level settings can conflict with the more high level settings offered through Windows. As a rule of thumb, you should avoid having both the BIOS and Windows Power Management settings configured, particularly if this configuration is resulting in problems on the computer. So, we will need to check whether there are any power management settings in the BIOS which may be causing this problem. Please be aware that modifying the computer BIOS is a sensitive and potentially dangerous process, as wrong moves could result in your computer becoming unbootable. Please proceed at your own risk and only if you are confident modifying critical system settings. Should you wish to proceed, restart the computer. During the POST (power-on self test) when the BIOS messages are displayed, or alternatively the computer manufacturer’s logo is displayed (in the case of brand-name computers), you should see a message saying ?Press to enter setup?. When this message appears, press the nominated key to enter the BIOS setup. Once in the Setup, go to the Power Management section and inspect the settings. Pay particular attention for any settings which may potentially conflict with the Windows settings. Unfortunately I cannot provide exact guidance on the procedure to follow, as all types of BIOS setups have different layouts and configurations, so you will need to rely on your own judgement. However, I strongly recommend that you write down the original value for any settings before making changes, in case you need to revert to the previous setting. Once you have finished, save and close the BIOS setup and restart the computer to check whether the problem has been fixed.

There may be other solutions to this issue, and if any other readers have suggestions on how Denis could resolve this power management issue then please write in and I will pass your suggestions onto Denis.