How To Speed Up A Slow Computer

How to speed up a slow computer. A slow computer is no fun – it takes a long time to start up, programs take ages to open, ‘Not Responding’ messages appear and using it is like wading through treacle…

Although there are many reasons why it might be running slower than it used to, most of the PCs we see in our repair business have been slow for months and are caused by the common problems reviewed below which bring together in one place a number of topics we have featured recently:

Problem 1 – Too Many Temporary Files. Solution: Easy fix, free, minor improvement in speed.

Temporary files can slow down Windows and other programs (because they have to load up thousands of these useless files every time they start). If you have never deleted them you may have thousands of these stored on your PC. Delete them by following our guide to delete temporary files with Ccleaner. It is worth doing this on at least a monthly basis.

Problem 2 – Too Many Programs Running at Startup. Solution: Medium fix, free, potentially significant improvement in speed.

Every time your PC starts, many unwanted programs also start up in the background – sucking power from your processor and memory and making your PC or laptop run slower. Weed out these unnecessary programs and speed it up by following our guide using Msconfig.

Problem 3 – Not Enough Memory (RAM). Solution: Advanced fix, not free but potentially huge improvement in speed.

Lacking enough memory (RAM) is by far the most common cause of a PC running very slowly – especially common in Vista and XP. Check to see if adding more RAM will make your computer run faster. If you need to add more memory but can’t afford to, go back to Problem 2 and be more ruthless in weeding out unnecessary programs because the more programs you remove from Startup the more of your scarce RAM will be freed up.

Problem 4 – Leaving Another User Logged On. Solution: Easy fix, free, potentially significant improvement in speed.

If you only have one user account, skip this problem. Ever since Windows XP, if you have more than one user account set up in Windows, there has been an option to switch quickly from one user to another (Fast User Switching). The advantage is that you don’t have to save your files and log off just so someone else can use their own account for a moment – you can later switch back right to where you left off.

Sounds too good to be true? Unfortunately it is – not logging off means that up to half of Windows resources are kept tied up by the original user. If you were short of memory in Problem 3 above then it will be a whole lot worse if you use Fast User Switching. The simple way to avoid this is to save your work and log off in the normal way before letting another user log on – do not just switch users.

Problem 5 – More Than One Antivirus Package. Solution: Easy fix, free, potentially huge improvement in speed / reliability.

Antivirus software is essential nowadays but you should never have more than one full antivirus package as it will significantly slow it down and may even cause crashes or failure to start up into Windows. A full antivirus package consists of Antivirus software and a Firewall – to clarify:

If you have free antivirus software like AVG or Avast you can also install a firewall like Zonealarm or Comodo because most free antivirus software does not include a firewall of its own – but do not install both AVG and Avast or both Zonealarm and Comodo.

If you have a paid security suite like Norton or McAfee they usually include a firewall of their own so do not install any other antivirus package or firewall (whether paid or free). If you do have more than one full package then uninstall one of them to speed up your PC and make it less prone to crash.

Problem 6 – Hard Drive Problems. Solution: May require Advanced fix, not free.

A failing hard drive or one that is stuck in PIO mode will cause a PC to run extremely slowly – see our articles to check if a hard drive is failing and fix a hard drive stuck in PIO mode. If your hard drive is failing the only permanent solution is to replace it or buy a new device.

If your hard drive is not failing but is old (more than 3 years) it will be slower than modern drives. However, it is rarely worthwhile replacing it purely for a speed increase because the rest of the components (e.g. processor and memory) could still act as a bottleneck – without upgrading them too the potential speed increase may be minimal.

Problem 7 – Viruses and other Malware. Solution: Advanced fix.

Although viruses and other malware like worms and trojans may slow things down, this is usually the least of the problems they cause – you may find that you cannot open programs at all or be unable to get rid of messages warning you of all sorts of errors.

Of far more concern than slow speed is removing the malware for security reasons – and to protect your data. See our article on how to remove viruses.

Problem 8 – Old Windows Installation. Solution: Advanced fix.

Windows itself will naturally become slower over the years as you install more programs, updates, fixes and tweaks – the registry becomes more bloated, drivers become outdated and databases used by Windows are not optimized as they once were. A solution to this gradual accumulation of clutter is to reinstall Windows from scratch, taking a backup of your personal data first.

This also gives you the chance to only reinstall programs/drivers which you really need, cutting down on garbage such as software from a long dead printer – enthusiasts will often reinstall Windows annually to keep it in peak performance.


There are many ways to speed up a slow computer without having to break the bank. Follow these tips to optimize Windows as much as possible and review them on a regular basis – it is also worth performing a regular computer service to tune it up.

3 thoughts on “How To Speed Up A Slow Computer”

  1. ok here’s something to add in your list:

    go to run or simply press win+r then type prefetch then delete the files in that folder.

    add virtual memory (swap file in linux systems) go to advanced options in my computer. set it between 3000 to 4000 mbytes

    thanks all for now.

    • It’s not advisable to delete prefetch items without a good reason – they’re used to speed up program load times so deleting them will generally make the computer slower until all the most used programs have re-populated prefetch.

      Virtual memory in modern computers is best left to Windows to manage the size (if you have enough memory it isn’t going to be an issue anyway) although there may be a performance gain in moving the swap file to a different partition or hard drive (if it is at least the same speed as your primary system drive)

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