Whenever I put my Windows Vista computer into sleep mode it goes through the power down procedure but within 30 – 60 seconds the computer wakes up again. The computer is running Windows Vista Home Basic.

There could be several reasons for the computer waking from sleep mode, with the most common being some device which is connected to the computer. Windows can allow particular devices to wake the computer from sleep, as the device may need to perform some kind of function which requires the computer to be awake. For example, should you have a fax modem connected to the computer, allowing your computer to receive faxes, if there is an incoming fax the computer will need to be woken so that it can receive the fax. This can be convenient in such situations, but it can also be quite inconvenient when the device is waking your computer for no particular reason. Additionally, it can be quite difficult to track down the device which is causing the computer to wake. In any case, we will start at the beginning to see whether a connected device is the cause of the problem. As a starting point, shutdown the computer and then disconnect all non-essential devices from the computer. If the computer is a desktop computer, the only connected devices should be the monitor, keyboard and mouse. Note that if your monitor functions as a USB hub to the computer, make sure you disconnect the USB cable going from the monitor to the computer, otherwise any USB devices which are connected to the monitor’s USB hub will remain connected to the computer. In the event that you have a laptop, you should have nothing connected to your computer at all (since the monitor, keyboard, and trackpad are built into the computer).

Once all connected devices have been disconnected from the computer start the computer and check whether the problem continues. In the situation that the problem does not persist, one of the devices which were previously connected to the computer seems to be the root cause of the problem. In this situation it is a case of trial and error to determine the exact device causing the problem. I suggest that you shutdown the computer, connect one device, then start the computer and check whether the problem occurs. Should the problem not occur, the device which you connected is not the device causing the problem. In this case, shutdown the computer, connect another device, and start the computer then check again. Continue this procedure until you connect a device and the problem occurs, at which point you know the device causing the problem. Once you have determined the device causing the problem we need to figure out how to fix the problem. As a first step we should check whether the device has been configured to bring the computer out of sleep mode. Go to the Start button > “Control Panel”. In the window that appears in the left-hand pane click “Classic View” and then open the “System” control panel. When the next window appears in the left-hand pane, click “Device Manager”. This will display all devices connected to the computer. Find the device which is causing the problem then right-click on the device and select “Properties”. In the Properties window that appears for the device, click the “Power Management” tab. Make sure the option “Allow this device to wake the computer” is unticked. Click OK to save and close.

Should the device already have the option to wake the computer unticked, or changing this option does not resolve the problem, there could be a drive problem with the device. The most likely cause would be a driver incompatibility with Windows Vista, especially if this problem has existed for a while and the driver being used may not have been designed for Windows Vista. Therefore, I suggest that you visit the manufacturer’s website to check whether any updated drivers are available for the device and, if so, download and install the updated drivers.

Dealing with a different scenario, if you disconnected all the devices from your computer and the problem still remains this means that the problem is either being caused by one of the devices which remains connected (i.e. keyboard, mouse or monitor) or there is a software problem causing the problem. Dealing with the first possible scenario whereby one of the devices which remains connected is causing the problem, I doubt the monitor is causing the problem since that is only connected to the computer via a DVI or VGA port which is transferring video data, so it should not be causing any power management problems. However, if you are using a special type of keyboard or mouse (e.g. wireless or Bluetooth) that could be the issue. If possible, try connecting a standard wired keyboard and mouse to the computer to check whether that makes any difference. If so, then you know the problem is related to the keyboard and/or mouse. In this situation, you need to track down the problem to either the keyboard or mouse (or combination of both) and I would then suggest you look at updating the drivers in case they are causing the problem.

Dealing with the last possible scenario, where none of the connected hardware devices are causing the problem, the root cause of this problem appears to be software related. We should first check the power management settings in Windows Vista to make sure that everything is in order and nothing has gone awry. Go to the Start button > “Control Panel”. In the window that appears, click “Classic View” in the left-hand pane and then open the “Power Options” control panel. Go through the settings and make sure that everything looks in order. For example, on my computer the power management has been set to “Balanced” and everything seems to work well.

Once you have checked the Windows power management settings it would also be worthwhile checking the computer BIOS power management settings. These are the settings contained on the motherboard of the computer itself and operate at a very low level. Please be aware that accessing and modifying the settings in the BIOS setup for your computer is a potentially hazardous process which could result in your computer no longer booting correctly. Making the process even more difficult is that I cannot provide step-by-step instructions for checking your power management settings as each computer is different. However, I can provide general advice. So only proceed with this procedure at your own risk and if you are confident working in the computer BIOS. Should you wish to proceed, restart the computer and when the computer boots and completes the power on self test (you should see the manufacturer’s logo appear on screen during this process) there should be a message saying something like “Press F2 to enter setup”. When this message appears, press the nominated key to open the BIOS setup. When in the BIOS setup, go to the Power Management or Power Settings portion of the setup. Make sure all the settings look correct and there is nothing within which looks wrong. If you are unsure about any settings do not change them, but instead contact me again for further advice. Once you are done, exit the BIOS setup and save changes (if required) and the computer will reboot.

Should the settings in the BIOS setup not help resolve this issue, the final possibility is some piece of software on your computer is conflicting with power management. To test this theory we will close all programs and background processes running on the computer to see whether the problem continues or stops. When Windows has finished loading close any programs which are running, including those in the Windows system tray (i.e. bottom right-hand corner of the screen, next to the clock). Once all visible applications are closed we need to close any processes which are running in the background. Press CTRL-ALT-DEL to open the Windows Task Manager. In the window that appears click the “Processes” tab. Click on the “User Name” column heading to sort the processes by user name. If the User Name column is not visible go to the “View” menu > “Select Columns” and tick “User Name”. You need to close all processes running under your user name except “explorer.exe” (which is the Windows graphical user interface) and “taskmgr.exe” (the Windows Task Manager, which you are using to close the other processes). Make sure you only close processes which are running under your user name and no others. Once all the processes have been closed check whether the power management problem continues. If not, one of those programs or processes was causing the problem. In this case, it is a process of elimination to determine the exact program or process causing the problem. Restart the computer, so that all the programs and processes restart upon bootup. Then, start by closing one of the programs and check whether the problem persists. If so, close another program and check again. If you exhaust all the programs and the problem still occurs, move onto closing the background processes using the Task Manager, each time checking whether the problem has stopped. Continue this process until you close a program or process and the problem stops, at which point you have determined the program or process causing the problem. At this point you will need to determine whether there is a method to stop this program or process from interfering with power management. I suggest that you try searching Google or like for the program or process name to see whether any other people have had the same problem and found a resolution. If you need further assistance then please contact me again.