Apr 29

11 reasons for your computer running slow and how to fix it

6. Damaged sectors on Hard drive

This is another very common cause of a slow computer that is often either bypassed or not even considered.


The most obvious sign is constant activity on your hard drive. This is because if the drive has a bad sector the computer tries to read it anyway until it reaches its timeout and moves on. Bad sectors on a hard drive CAN but not always mean that it is time to replace your hard drive with a new hard drive. The first step is to run a disk check on the drive to see if that resolves the issues.

Related Post: Running a disk check

If you cant run check disk from windows try: Repairing Unmountable boot volume

7. Clogged up system

Over time a computer system can start to become clogged up with leftovers from programs we have installed and uninstalled, leftover installation files, temporary files. As well as clogging up the system they can take up a significant amount of space if left unchecked for a long period of time.


There are a number of tools out there that can help you cleanup these types of files follow the 2 links below.

Using the disk cleanup utility in windows

Using CCleaner to clean up temporary files

8. Registry problems

Warning: The registry is the most important part of your operating system. Be sure to have backups of your data and the registry before performing any actions on it.

The registry is the brain of you operating system and fiddling with it is not recommended in most circumstances. There are a lot of programs out there that you pay for that claim to clean your registry but in my experience most of them do more harm than they do good.


CCleaner also has a built in registry cleaner that you can use. This program also allows you to make a backup of the registry before doing any work on it.

There is one tool I have used for a long time that I have always found useful and has never caused any problems for me and is also free.

Free Windows Registry repair.

If free software is not enough you can always try the popular FixCleaner which is not free but is much more powerful and quite highly rated. You can download FixCleaner at FixCleaner PC Cleanup

9.Bad memory modules

Although the symptoms are usually more severe when you have bad memory (blue screens and crashes) faulty memory can sometimes be a cause of a slow computer and it is worth ruling it out with the tool below. Ensure you run the tool for at least 2 passes.


Check your memory using memtest

10. Not enough memory

If you have a pretty old computer it could simply be the your computer is not designed to run what you want to run on it. When your computer was first purchased 512mb memory was probably enough for windows XP but nowadays running a computer on anything less than 1GB is asking for trouble especially since we have all these service packs and security updates installed as well as the bigger memory and processor requirements of the software we run.

My personal recommendations are based on experience

  • Windows XP – Minimum of 1GB
  • Windows Vista – Minimum of 1GB (Highly recommend 2GB+)
  • Windows Seven – Minimum of 2GB (Highly recommend 4GB+)

You can check the memory you have by right clicking on your computer icon and selecting properties. You will see the amount of memory you currently have under memory.

You can also see the current amount you have installed and the amount your computer can support via crucial memory.

Simply go to Crucial.com/uk and select the system scanner. Allow the software to install and it will then scan your system and inform you of the current memory along with the maximum amount it can support and the price to upgrade the memory.

It is then a case of swapping the memory out and replacing it with the new memory.

11. Clogged up fans

Dust is a computer worst enemy. You would be amazed at how much dust a computer attracts.

A computer needs to breath. Its fans on the inside are designed to cool the processor and other pieces of hardware. If the computer/Laptop gets too hot it can overheat.

The first sign of a computer overheating is a dramatic slowdown after it has been on for a little while. This can but not always be followed by blue screen error messages or the system unexpectedly shutting down. The reason it does this is to protect itself from burning out.


If you are using a desktop open the casing and carefully hover out any clogged up dust from the inside and in particular around the fans and heat sink. If you can pick up a can of compressed air and blow out the fans and heat sink.

If you are using a laptop your only choice is a can of Compressed Gas Duster it is relativly cheap for the hassle it can save you in the future. You will see vents on the bottom and side of the laptop , use compressed air in these vents to blow out any dust blocking the fans.

As simple as it sounds it can make a very significant difference to the running of your computer. As a matter of course I clear out all my computers every 3 months and it still amazes me how much dust I find stuck to the fans. People with pets tend to find that their fans will get a lot more clogged up.


  1. abieanarna

    Aside from malware always find sometime to defrag your laptop/computer, always update your anti virus. Anyway nice article hoping you’ll feature more.

    1. You are right. Some people say defragging is a waste of time but I find it helps especially if your drive is heavily fragmented

  2. Dolores

    I was very pleased to find this site. I wanted to thank you for this great read!! I am definitely enjoying every little bit of it and i have you bookmarked to check out new stuff you post.

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