1. Hardware conflicts.
Sometimes two components in a PC will try to consume the same resources or perform the same task. This creates a hardware conflict, and it manifests itself in unusual behavior during certain tasks. An audio conflict, for example, might disable audio in some programs, but not in others. Not all conflicts will crash a PC, but some can cause instability, which leads to a Blue Screen Of Death and/or a reboot.
2. Random File Or Program Corruption Issues
A classic sign of a slow-growing problem is random file and program corruption errors. Files that always worked suddenly don’t open, or only work on occasion. They may or may not be accompanied by an error message. Several issues could cause this problem. First, make sure your anti-virus is running and up-to-date, and then run a full system scan for malware. A virus sometimes will cause random file corruption issues. Another likely culprit is a failing hard drive, so you should check it for errors. And if that doesn’t reveal the problem, look for hardware conflicts in the Windows Device Manager; a driver issue might be responsible.
3. Slow, Unreliable, Or Noisy Mechanical Hard Drive
Mechanical hard drives are likely sources of problems in modern PCs. Though they’ve become more reliable over time, they still contain mechanical parts that will eventually wear out, and that makes failure a reality users must prepare for.
If you find that programs are taking a long time to load, that files don’t always open, or that the drive has become louder while working, then your hard drive could be nearing the end of its life. You should check the drive for errors, but don’t consider yourself problem-free if none appear. Backup your data just to be safe.
4. Occasional Boot Errors
A sure sign that something has gone wrong is an occasional error when booting your PC, usually something along the lines of “boot device not found.” Windows will fail to boot, but it might work at a later time, even immediately if you hit the reset button. This is a sign that something is wrong with your hard drive, or that your Windows installation has somehow become corrupt. Replacing the drive and/or re-installing Windows is usually the only fix. However, before doing either, do make sure that you haven’t mistakenly left an external hard drive or USB drive plugged in. Some PCs will try to boot from a USB device before the hard drive, and that will cause a boot error.
5. Poor Performance
General poor performance, from launching programs to watching YouTube video and playing games, often results from the cumulative effects of software installed on a Windows PC. If you’re not careful, you may find you’ve installed more than your computer can handle, and it will perform poorly. Cleaning Windows might help, though if your case is particularly bad, you may have to re-install the operating system.
If the problem persists, then hardware is probably the culprit. Try some free benchmark programs, record the results, and use them to determine what part is slowing down your PC. You can then decide if it should be replaced.
6. Spotty Or Unreliable Internet, Even Over Ethernet
Unusually, poor Internet performance that can’t be linked to a problem with your ISP or router is often a bad sign. It may mean that your WiFi or Ethernet adapter is encountering problems, or it might be a sign of malware robbing your bandwidth. Eventually, the problem might make Internet access impossible or, if the source is malware, your PC could suffer permanent damage.
Download a bandwidth meter for your PC to see how your home network is being used. If bandwidth is being consumed when you’re not using your computer, malware is likely the problem, so check out our malware removal guide. If there’s no unusual usage, then the problem is likely with your adapter, and it will probably need to be replaced.
7. Video Artifacts
The video that you view on a PC, no matter its source, is effectively a stream of data that’s turned into an image. An error in that data can cause an “artifact,” which might appears as blocks of random color, strange lines or partially missing 3D geometry.
All of these problems are signs that your PC’s graphics processor is encountering an issue. Often the problem is excessive heat; you may just need to open your computer and give it a good cleaning. If that doesn’t solve the issue, then the GPU is likely on the out, and should be replaced.
At times you may have difficulty deciding if an artifact is caused by the video card, or by a bug in a game, or by poor video compression. A video card stability test can help you determine the source of the problem.
8. An Unusually Loud System Fan
A computer with fans that are louder than normal may be screaming for help because its internals are too warm, a situation that can eventually lead to a crash and even hardware damage. You can use a PC monitoring tool like SpeedFan to investigate the problem and see what temperature your CPU and GPU are reporting. If the situation seems heated, open up your desktop and clean out its fans with a can of compressed air. Laptop owners have fewer options, but you can still try to clean out the exhaust fan, or buy a cooling pad.
9. Software And/Or Adware Launches At Random
Software that launches without your permission is a clue that you may become a victim of malware. Often the programs that appear will be linked to advertisements, but any Trojan can allow this avenue of attack. You might also notice that certain hardware, like the webcam, may activate without your consent. Eventually, this tampering might lead to problems as your PC is slammed with unwanted programs or its files are corrupted maliciously.
Solving this problem is simple in theory, but difficult in reality. Read our malware removal guide to find out the best ways to clean up after an attack. Alternatively, if your files are backed up and you don’t want a lot of hassle, you can perform a clean re-install of Windows.
10. Windows Crashes While You’re Not Looking
You may already have a computer that has crashed, but not while you’re looking. Perhaps the PC was left to go into sleep mode, or just left on overnight.
The fact the PC hasn’t crashed while you’ve been using it is likely due to luck and shouldn’t be considered a symptom. In most cases, this situation is caused by a driver or hardware issue that’s triggered at random or when an exact set of circumstances are met. If you haven’t already checked for hardware conflicts, do so now.
Should no conflicts be obvious, try updating the drivers for your video card, sound card, motherboard and WiFi or Ethernet adapter. If the problem persists, run benchmarks to see if the stress causes the error to emerge. And should that not work, you may have to resort to trial-and-error by disabling components to see if the problem goes away. You might also investigate if there’s any software scheduled to run overnight on your PC, such as a backup or anti-virus, which could be triggering the crash.