Expert tips on how to fix a PC or laptop that won't start up and boot into Windows.
If your laptop or PC won’t turn on, don’t panic. You might be able to fix it yourself for free by trying these five methods.
Here we'll explain the possible causes and how to try and fix a PC or laptop that won't boot up.
1. Check the power supply
Laptops
This is one of the most common problems. There are various things that can go wrong, from using the wrong laptop power supply (delivering the wrong voltage) to a blown fuse in the plug.
It might be that your power supply has simply failed. First, make sure the battery has some charge. If you’re not sure, and there’s no power indicator on the battery itself, then remove it entirely and just use the mains charger.
Double-check, too, that the charger is the right one for your laptop. Many laptops – especially from the same manufacturer – use the same size plug, and if you own more than one, it’s not too difficult to plug in the wrong power supply, which might provide a different voltage or not enough current.
Other gadgets may also use the same tips, such as a battery powered speaker, and are unlikely to use the same voltage as your laptop, which typically requires 16-20V.
Second, check the fuse in the plug. Use a screwdriver to remove the fuse and install one that’s known to be good. If you have a spare power cable that will plug into your power supply, this is a much quicker swap to test that it isn’t the fuse at fault.
Check over the wire itself, as power supplies get beaten up, especially if you carry them everywhere. Weak points are at the ends where it joins the black brick and at the plug which connects to the laptop. If you can see the coloured wires inside the black outer protection, it could be time to buy a new PSU.
PCs
PC power supplies can also be problematic. Few people have a spare they can install and test, so the first check is the fuse in the plug. There's also a fuse inside the PSU itself, but it will require you to remove it from your PC and then remove the metal case to check if that's the problem.
One of the most common PC power supply issues is that the PC will turn off unexpectedly rather than fail to boot up at all.
If the LED is on showing that power is reaching it, make sure your power button is properly connected and working.
You can short the appropriate motherboard pins together (check which ones in your motherboard manual) to eliminate the power button from the equation.
2. Check the screen
Laptops
Try disconnecting any external displays including projectors and monitors to make sure they're not stopping your laptop from booting into Windows.
If your computer's power LED lights up and you can hear the hard disk or fan(s) whirring, but there’s no image on the screen, then make the room dark and check that there isn’t a very faint image on the screen.
It’s easy to think a laptop isn’t booting when in fact, it’s the screen that’s the problem.
If there is a faint image – maybe the Windows logon screen – then it’s likely that your screen’s inverter has failed. This component changes the direct current (DC) coming from the battery or power supply to an alternating current required by the screen.
Replacing an inverter isn’t too difficult if you’re handy with a screwdriver, but it’s crucial you buy the right replacement part. As inverters aren’t exactly cheap, you can’t afford to get it wrong.
If your laptop appears to be booting fine, but there’s no image at all, the LCD panel could be at fault. Replacing a laptop screen is possible, but difficult, and screens can also be costly. If it’s an older laptop, it’s worth considering buying a new one.
PCs
There isn't much you can do to fix a broken PC monitor, but it's easy - or easier - to swap the power lead and video cable or even the whole monitor to see if that's the reason your PC won't boot.
3. Boot into Safe Mode
Even if you can’t boot into Windows, you might be able to get into safe mode. Press F8 as your laptop is starting up and you’ll get a menu offering to boot into Safe Mode.
If you can enter safe mode, you might be able to undo any changes that caused your laptop or PC to stop booting. You could try uninstalling any new programs that you recently installed, uninstall a driver that was recently updated, or create a new user account if the account is corrupt.
If you see an option to repair your computer, try this, but you will almost certainly need your Windows CD for this to work.
If you can’t get the drive going again, it’s time to start afresh with a new hard drive. Let's hope that you have a recent backup of your important files!
