PC Troubleshooting Guide – Why Your PC Stops Working

One of the most frustrating things in the world is getting up in the morning to see that your computer refuses to boot, or it keeps restart by itself. It was still working fine the night before, and you have totally no idea why it stopped working now.

In this PC troubleshooting guide, we will show you the possible problems that could happen to your PC and how you should fix it.

1. Your Memory Is Corrupted


One of the most common problem that I always encounter while troubleshooting a PC is that Windows stops working inexplicably at random intervals. Most of the time, it is the memory RAM causing the problem. The easiest way to verify this is to swap the RAM cards in your PC with some spare ones and test to see whether this works or not. Of course, if the RAM cards aren’t easily accessible, you can run memtest as an alternative. Corrupt bits of memory can cause a computer to act funny, and even crash, every time it starts.

Solution: The only way to solve a memory problem is to replace it with new memory. You will most likely end up replacing all of the memory sticks (usually two to four).

2. Switched Boot Order

When you can’t boot up your PC, it could be due to a switched boot order where the system cannot find the partition to run the bootloader. This usually happens when your CMOS battery (a small round battery found on your motherboard) runs out of juice. It could also happen if you (or someone else) have accessed the BIOS recently and changed something accidentally. You’ll know your boot order was switched if you get the “no operating system found” error when starting your computer, or something else besides your operating system’s loading screen.

Solution: access your BIOS (press “F2” or “Del” button when the BIOS screen appear) and reconfigure the boot order. Your boot order should look like this:

  • CD/DVD Drive
  • Hard Drive
  • Everything else

If your configuration already looks like this and it still cannot boot up, check your CD ROM and eject any disc that are in it, then restart.

3. Corrupted Bootloader

If the above solution does not work, your problem could be due to a corrupted boot loader.

The Solution: Use Super Grub Disk to fix the bootloader.

4. Registry Issues (In Windows)

Your Windows Registry holds important information to your system, and it can often cause problem when it is mishandled. This happens when an application write into a key that doesn’t belong to them. They also could be caused by viruses built to sabotage your computer’s resources. That’s why it’s good to back up your registry once in a while. You’ll know that you have registry issues when there are errors on startup, often leading to using your PC in safe mode.

The Solution: Use CCleaner and nCleaner. They will eliminate things that don’t really belong in the registry. If a program wrote over something system-based, however, it usually cannot be fixed without either restoring a backup of the registry or re-installing Windows.

5. Hardware Is Sending Bad Signals

This one is a common one in systems with Windows XP or earlier, but isn’t uncommon in Vista and later systems. Usually, hardware problems of this nature happen because the wrong driver was installed for a certain piece of hardware. As much as Windows tries to mitigate hardware issues, they will happen at one point or another regardless of how careful you are.

How to Find the Issue: You can see where hardware conflicts occur by accessing the Device Manager. In Windows 7, you can click the “Start” menu, type “Device Manager,” and press “Enter.” In Windows 8, access the Start screen and just start typing the name followed by the “Enter” key. Conflicting devices are often shown with an exclamation point next to them. To find out the cause of the problem, simply right-click the device and click “Properties.”

The Solution: You must uninstall the driver for that specific piece of hardware and then install the proper one. This will take some searching unless you still have its instruction manual. This often happens to video cards and hard drive controllers, although sound cards and virtually anything else are prone to such issue. Once you install the correct drivers for your hardware, restart the computer.

6. Corrupt Clusters in Hard Drive


Corrupt clusters within your hard drive might cause your computer to crash (either Blue Screen of Death, or the PC restarts), especially when trying to access a file. If you feel you have this problem, you can confirm it by performing a maintenance check on your hard drive. You should do this at least once a month.

The Solution: If you would like to scan your hard drive for problems and fix them along the way, read the question asking “What’s the best way of finding out my hard drive’s health for free?”

7. Improper Airflow

It might seem like a trivial issue, but PCs can suffer from airflow problems that prevent them from cooling down effectively. You can almost identify this immediately when the CPU’s or graphics card’s fans start to whirl loudly.

Causes for this could be a dirty, or spoilt fan, the heat is not directed to the case opening, or that the heat sink is not dissipating the heat effectively. In case you are wondering, here’s what a heat sink looks like:


The Solution: Check the fans. If they’re dusty, clean them. If they’re making noise, replace them. Also, check the direction in which the air is flowing (by checking the direction of the fan rotation). A computer’s airflow ideally should match this diagram:


8. Infection

Viruses are nasty things that usually make a part of the computer – or the entire system – exaggeratedly slow. Some of them also intentionally or unintentionally crash your computer. After analyzing a lot of the code inside of a virus, it’s more often the latter than the former because the programmers who wrote the virus didn’t really have your computer’s longevity in mind.

The Solution: To quickly determine what’s wrong, get your hands on Microsoft Security Essentials or AVG’s free antivirus. It’s worth a try. They’ll eliminate the threat and hopefully restore your computer to working order.

9. Corrupt Software

When software uses the hardware-software bridge to communicate with your hardware, it might just be speaking a bunch of gibberish that causes Windows to crash. This happens especially with software that’s newer than the operating system you’re using, but some old software does this as well.

The Solution: Try using an older version of the software. If that doesn’t work, then you’ll probably have to renounce using the software entirely and try alternatives. If you use MS Office 2010 and it keeps crashing your computer, you might want to switch over to the 2007 version, for example. This works more often than you may think!

Did We Miss Anything?

If you know of another problem that’s easily solved when troubleshooting a PC, let us know by commenting below!

Miguel Leiva-Gomez Miguel Leiva-Gomez

Miguel has been a business growth and technology expert for more than a decade and has written software for even longer. From his little castle in Romania, he presents cold and analytical perspectives to things that affect the tech world.


  1. If there is a problem with the Windows Registry and the user can’t login to the computer, Last known good configuration can always prove beneficial in this case.

  2. Graphics card not fitting securely into the slot. I have found graphics cards to be a common cause of boot up failure or random hang ups. The problem can usually be solved by re-seating the card in the slot. In some cases it can occur frequently. I think the problem occurs as a result of the motherboard expanding and contracting as it heats up and cools down and this results in slight movement of the card in the slot. Memory modules also appear to do this but in my experience cause less problems than graphics cards.

  3. my message when I run a computer check says I have an antique driver and when I let the computer fix it, then I don’t have sound on my computer.

  4. my mouse is driving me crazy. it’s ‘jittery’. i can’t scroll with the wheel anymore- have to use that slide thing on the rt. side of the page.i did the speed adjustment thing and that ain’t it. plus, i tried the ‘system mechanic’ aol is pawning off this month. pcmatic was my little fix-it thing and i was waiting for my cheapie renewal and am screwed big time(for me). i just clicked “fix it’. and now my active x is not supported,long running script makes my game site stop then start up,can’t logon at pcptstop site coz some scripting thing is not turned on-can’t download pcmatic user guide coz my “current settings don’t allow this file to be downloaded”.oh! my temp internet files- after a ‘fix it” with sys.mech.i had NOT ONE file,cookie, or anything to delete. and now i have HUNDREDS of all sorts of things and when i ‘delete’- it is quick and not much is gone. there’s no total at the bottom telling how many i have like it always did b4.lots of those “red babies”(infant view?) and that’s never been there, or maybe a couple i didn’t notice. i have fumbled my way thru figuring out how to do things and have fixed some weird things gone wrong BUT i don’t understand real ‘puter talk-folders,files, .exe, line:13. my puter is a plaything. games,youtube, ‘just sayin'(love that!). i can’t copy and paste–don’t laugh! so, if you dare to try to help me with any of this PLEEZ be really easy with me or i’ll cry. nah, i’ll figure it out. well, i’m done. i know you think i’m a full-blowed moron-probably am. my blond comes from a bottle and i usually figure it out- but i’m tired of fixin what ‘the only tool you ever need to make your puter run perfectly!’ that registry cleaning is not to be played with- and i just hit that ‘fix it’ button! i’m gonna stop now. i do feel better. not so stressed. thanx for giving me hope that tech can be easy. bye peteyk (linda)

    1. Word of advice, don’t mess with any registry programs. There is literally over 100,000+ registry entry’s. And these so called registry programs cannot determine what all is good from what all is bad. 9 times outta 10, those programs do more harm than good. At this point, your probably better off doing a complete restore of your windows. Not a system restore, but starting from scratch. I don’t even mess with windows updates. The only updates I mess with from windows updates, is major updates or any updates that have to do with drivers/hardware on my system.

    2. So interesting I must comment even though I have no solution. Asus K50IJ, preinstalled w/win7 x64 upgraded to win8 x64. Had same on win7. Checked/unchecked carret browsing, fooled with the ease of access (mouse), just about everything, still had mouse that followed the cursor around. Lately, after upgrading, it began again. I had so many installations of “mouse” it was ugly. I began by removing all references to “mouse” I could find (I am NO expert, in fact I’m old as dirt and dum asa rock). I reinstalled the driver for optic mouse (Walmart o-no) and it worked. I then installed the newer elan gesture touchpad and set them both to operate. I have a bit of an issue with the type following the cursor around but NOTHING like it was prior. I couldn’t find anything and spent literally months researching and searching. Best luck smiles4miles vmd

  5. I can relate to your comment about the air flow as I have noticed my fans have stopped working on the Aero Cool console. I get a pc hang up each time my computer starts up, but the strange thing about it is that it only does it once after initial bootup, usually within the first hour of operation then the pc can be left on for 24 hours and it won’t happen again. That I find most strrange. My operating system is Windows 7 Pro

  6. I had a 2-year desktop with Vista Ultimate fail to power up. The power supply was OK but the problem was the motherboard. Solved by buying a new desktop.

  7. Bill, Buying a new desktop can’t fix anything, you said buying a new desktop fixed your problem, but it didn’t fix your old computer.

    1. Lol. I agree. That’s like a car mechanic saying they fixed your engine problem by swapping out the engine with a new one. These days most computer tech’s don’t know shyz. They only think they know is, format & reinstall.

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