In the realm of computing, few things are more disturbing than a PC crash. Thoughts immediately turn to the valuable data you might have lost and that backup you intended to do - but never did.

In practice, things are rarely as bad as they first appear. Unless you’ve suffered a hardware failure, and specifically a hard disk crash, in all probability your data will still be intact. Here we’ll show you how to find out what’s gone wrong and recover from it.

Hardware faults

With the exception of some intermittent faults, some of which can easily be cured, our emphasis is on software-related issues. Before we start, therefore, it would be a good idea to make sure that the problems you’re experiencing aren’t due to a hardware fault.

If nothing happens at all when you try to turn your PC on, no lights come on and the fan doesn’t start, either the fuse in the plug has blown or there's a hardware fault with the PC itself, probably in the power supply. The chances are you won’t have lost any data but you may need to enlist professional help to repair your PC if you're not comfortable swapping out PSUs.

Alternatively, if lights do come on and the fans start but nothing appears on the screen or perhaps you get a Bios error message and Windows makes no attempt to start, the fault is probably connected with the motherboard, processor or memory.

It might just be an intermittent fault (on which we’ll provide some guidance later) but if that doesn’t work, again you’ll need expert assistance.

Finally, if your PC makes clicking or other unhealthy noises or if you see a BIOS error relating to the hard disk, it could well be a disk crash. Since this could result in data loss, take no chances. Turn your PC off and contact a data recovery company such as OnTrack.

Recent changes and updates

If your PC starts behaving erratically or crashing, the first thing to do is consider whether you’ve made any changes to your system recently. If the problems started immediately after installing some new hardware and its associated drivers, this would be a prime suspect.

In fact, if the crash is associated with the “blue screen of death” (BSOD), there might be a clue in the error message as to what’s happened - it might even list an offending driver.

BSOD blue screen of death

Conversely, if Windows always crashes or hangs while you’re running the same software, especially if it’s a package you’ve recently installed or upgraded, that’s a likely candidate.

Windows Event Viewer (search for “Event Viewer” in the start menu) is a useful utility that could shed some light on what’s gone wrong but it’s tricky for the uninitiated to get to grips with. For more information, see Microsoft's guide.

If the change is something you can reverse – uninstalling the new hardware and its driver, for example – try that. If it corrects the problem, look online to see if there’s a more up-to-date driver you could use instead. Failing that, contact technical support for the hardware in question.

Of course, if the problem is so serious that Windows won’t even start, removing suspect software isn’t ordinarily possible. In this case (and this also applies to using System Restore that we’ll look at later) the solution is to try starting your PC in Windows Safe Mode. This is a special mode in which all but the most basic and essential drivers and facilities are disabled.

Windows Safe Mode

While this doesn’t make your PC useable for everyday tasks, it will often run when Windows will not start normally allowing you to diagnose and cure system faults. To start Windows in Safe Mode, turn your PC on and immediately start pressing the F8 key repeatedly. When the Windows Advanced Boot Options menu appears, select Safe Mode.

System Restore & Windows Update

It won’t always be obvious what change has caused Windows to become unstable but there are measures you can take that could resolve the matter, nevertheless. Each time you make a substantial change to your system, and also at regular intervals, Windows stores the state of the system as so-called restore points that you can revert to later.

It would be a good idea, therefore, to try restoring your system to an earlier date. Be assured that the process won’t cause any of your files to be deleted, but recently installed software may be removed. Just search for “System Restore” in the Start menu and follow the instructions on screen.

Something else to check, if you’re suffering occasional failures, is that Windows is up to date. If you have automatic Windows updates enabled then your system should be fully up to date but, if not, you should check for updates.

Windows Update

Search for “Windows Update” using the Start menu and then click on Change Settings at the left. Now select “Install updates automatically (recommended)” from the menu. There are also utilities that will identify all out-of-date drivers on your PC and update them – some are free. Just enter “Driver Update” into Google but be sure to pick one that has received good reviews.

Next page: hardware problems and maintenance