After the computer has been turned-off for a period of time (a few hours) it takes more than 15 minutes to start-up again. While this is happening the computer whirrs away, but the screen is completely blank. Once the computer has finished booting-up (after the long wait) the screen is alive and everything works fine at a reasonable speed. However, if the computer is left running and goes to sleep then it can take up to another 5 minutes or more to wake-up. As you can see, it seems that the computer is a bit lethargic when waking-up from a dormant state! The strange thing is that if I shutdown the computer, and then immediately start it up again, it boots normally with all action visible on screen and is done in about a minute. Do you know why this is happening?

This is certainly an interesting problem since it does seem that your computer takes a while to come alive when it has either been shutdown or sleeping! The first possibility is that your computer itself is fine but something is wrong with the monitor. This could be giving the impression that the computer is not doing anything (since the screen is blank) and then suddenly comes to life, whereas in fact it may have been working fine all along but you just couldn’t see anything on the screen. The best test of this theory is for you to check what displays on the screen when it eventually starts showing information. If the Windows desktop displays then this gives a good indication that the computer was booting properly (and, most likely, at the correct speed) but because something is wrong with the monitor you had no way of knowing or interacting with the computer. Should this be the case then we need to take a look at the monitor for anything obvious. Check that all the connections are plugged-in securely (particularly the video connection between the computer and the monitor). If all looks alright then we need to determine whether the problem is the monitor or the graphics card in the computer, since the monitor could be perfectly fine but a faulty graphics card results in no video being sent to the monitor for display. The easiest and most reliable method for testing is to find a different monitor, which is known to work and check whether that works correctly on your computer. If you manage to talk a friend into loaning you their monitor and it works, it seems that your monitor is faulty. In this case I would recommend against trying to get the monitor fixed, simply because it will likely be cheaper to purchase a new monitor (unless it is under warranty of course, in which case you should speak with your warranty provider about getting the item fixed under the terms of the warranty).

However, should you find that connecting a different monitor to the computer does not fix the problem then our attention turns to a potential problem with the graphics card. To double-check this diagnosis, it could be worthwhile connecting your monitor to a different computer and check whether it works. If you find that the monitor works fine, then that confirms our diagnosis of an issue with the graphics card. This could potentially be a more difficult avenue to troubleshoot, since many computers come with on-board graphics – this means that the graphics card is part of the motherboard itself. This means that we can’t easily swap-out the graphics card in the computer with a replacement, although you could potentially install a separate graphics card in the machine (if there a spare expansion slot on the motherboard suitable for the graphics card) and check whether that works. Unfortunately, doing switching and swapping of graphics cards is much more difficult than monitors, simply because you need to take the computer apart, not to mention that it is more difficult to source a spare graphics card for testing (since generally friends aren’t willing to dismantle part of their computer to provide parts for testing, since the parts generally are not particularly robust either). Therefore, in this situation I would recommend that you take your computer to a repair shop since they will be much better equipped to swap parts for the sake of testing and, if the graphics card is not the problem for one reason or another, should be able to provide an alternative diagnosis.

The previous procedures have dealt with the situation where the Windows desktop appears when the monitor springs to life, indicating that the computer is working fine but there is something wrong with the video display (either the monitor or perhaps the graphics card). However, the converse of this situation is that when the monitor comes to life that it starts the computer boot sequence from the beginning. This obviously indicates that the computer has not been booting, but instead has been sitting there for the 5 or 15 minutes evidently doing nothing and then deciding to commence operation after that delay. This is quite strange, particularly since you mention that the computer works fine once it has successfully booted (as generally if there is a hardware fault this will impact on how the computer operates throughout the entire session, rather than just how the computer boots-up). That said, we cannot rule out a hardware related problem.

In my experience the two most common components which can cause strange computer behaviour is the memory and the power supply. As a starting point it would be worthwhile conducting a memory check on the computer just to make sure that all is alright. I suggest that you download a utility called Memtest86+ (www.memtest.org). This free utility will test the memory in your computer to check whether any is faulty or have developed faults that could impact on the performance of your computer. In the list of downloads on the Memtest86+ website, select the “Download - Pre-Compiled Bootable ISO (.zip)”. This will download an ISO file with the utility. The ISO file is contained in a ZIP archive, so once the download has finished, find the download on your computer and extract the ZIP archive so that you have the ISO file. An ISO file is essentially an archive of the contents of a CD, including the file system, making the ISO file an exact duplicate of the CD itself. You will need to burn the ISO back onto a CD which will then render the CD the same as the ISO file. In the case of the Memtest86+ ISO file, once it has been burned to a CD you will be able to boot from the CD and then run the memory tests. Be aware, you cannot simply copy the ISO file onto the CD. Instead, you need to use a program which supports ISO burning which will expand the contents of the ISO file and then copy that content to the CD. If your computer is running Windows 7 then the ability to burn ISO files is already built into the operating system – all you need to do is right-click on the ISO file and select “Burn disc image”. However, if you are running earlier versions of Windows (such as Windows XP or Windows Vista) then you will need to download a third-party utility to burn the ISO files. You can find a whole heap of free utilities for burning ISO files by searching Google, although I suggest that you read the reviews of these utilities before downloading and installing just to make sure that they meet your needs and are reliable.

Once you have your burned CD with Memtest86+, insert the CD into the drive and then restart the computer. Depending on the model of computer you may need to press some kind of key combination to tell the computer that it should boot from the CD drive instead of the hard drive. Nevertheless, once the computer has successfully booted from the Memtest86+ CD then it should proceed into the memory tests. You can expect a few errors, as memory is not always completely accurate, but if you start to get large numbers of issues occurring, then it could indicate that something is wrong with the memory in your computer. This could explain why it takes a while for your computer to boot-up from a cold start, because it is running some kind of memory diagnostic which fails and requires the computer to quarantine that section of memory (or maybe the computer doesn’t actually know what to do, and is just stalling until some kind of timeout!). Either way, you may wish to have the computer looked at and potentially have some of the memory replaced.

Finally, the power supply could be the issue. This is more likely to be the problem than the memory in the computer, but we have left this until last since there is very little that you can do. While the power supply does seem to be working (as the computer eventually boots and works as per usual) there could be something wrong with the supply resulting in the computer not receiving the correct amount of power and thus delaying the startup. While you could replace the power supply it is not guaranteed that this is the problem and, much like doing a swap of the graphics card, it will be very difficult to find a friend who is willing to lend you their power supply for testing since that really would require them to take their entire computer apart for the favour! Additionally, unlike graphics cards, power supplies are a bit more tricky, since different supplies have different wattages so you need to ensure that the power supply you install in the computer has a sufficient wattage rating to correctly power your computer. In fact, if you have recently upgraded your computer (or installed new components) then it is possible that the power supply in your computer is unable to provide the required amount of power, and thus has resulted in this problem. In any case, if you reach this point you probably need to take the computer to a professional for a diagnosis since you have likely reached the limit of what you are able to research and try yourself.