How can I find out why my Windows computer slows down?

Don February 1, 2010

My computer continues to slow down.

I have deleted temp Internet files, defragged, ran spyware and virus tool, have high speed internet access, yet it keeps getting slower and slower. I can’t figure it out.

Any suggestions?

  1. sean
    May 6, 2012 at 8:57 pm

    if your computer is atleast 3 yrs old and you have been running it everyday for a long time now. after you have check, cleaned, and optimized your computer. and its still running slow. then open your computer up and vacumn the inside of your computer, especially around the cpu, and all fan areas. after years of collecting dust you will definitely see why its choking and coughing.

  2. Rishi1592
    December 19, 2010 at 8:16 am

    install any 1
    and optimize your computer

  3. John
    August 20, 2010 at 4:05 pm

    In one way my suggestion is too late but once you have got your computer fixed perhaps by reinstalling the operating system - make an image of the operating system drive. There are free programmes but my favourite is True Image (my only connection is as a customer). Then your problems are over in the future. Whenever you want to have a new clean system you can simply restore your shining new system in a few minutes from a CD if you like. If you make any major changes that you're happy with just create a new image. If you buy a new computer as soon as you've got it make an image of the operating system hard drive.

    One other tip - modern computers have huge hard drives. If you can make sure your hard drive is partitioned and the operating system is running in it's own partition - It might be a good test of dealer to see if they'll do it for you.

    Before you do anything drastic, back up your data

  4. Sudeep K. Bansi
    August 14, 2010 at 5:03 am

    Really good info. My personal arsenal has CCleaner, Malware Bytes, Microsoft Secutiry Essentials and Avira Antivirus as the main weapons.

    • Aibek
      August 14, 2010 at 5:33 am

      Same here, but instead of Avira there is Avast

    June 28, 2010 at 5:35 pm

    Delete any programs you don't use, maybe add some more ram. Also, if you are savvy, you could backup all your files and wipe your hard drive and reload windows and all your files. Be careful with this though if you aren't familiar with what I'm saying

  6. Oron Joffe
    June 19, 2010 at 10:08 pm

    Judging from the question and the reactions above, it seems to me that there are two distinct tasks which are getting confused:
    1. Speeding up a slow computer and
    2. Finding out why it is slow.
    It's obviously better to do (2) before (1)! For that, you have to use process Explorer, mentioned above, or a similar program (Windows' own Task Manager is often enough) and look at the 'CPU' and 'RAM' columns, to see which programs are 'hogging' the computer's resources. If the CPU is not busy and memory use is not very high, then the slowness is probably disc-related.

    If you find that there are programs running which are not needed, then disabling them with a tool like Autoruns is a good test (you can always reenable later). Removing programs, and cleaning the computer of temp files and registry entries is going to help (I like to use CCleaner) and *then* defragging (try MyDefrag, it defrags *and* optimises the disc) will probably help, but you should make sure you've diagnosed the problem first, even if only provisionally, or you could end up spending the whole day optimising the wrong bits!

  7. Tom Leeono
    June 12, 2010 at 10:52 am

    Assuming you have enough memory the 2 key areas to look at are your registry database and drive fragmentation. This whitepaper explains this clearly:

  8. N Navin Raj
    May 12, 2010 at 6:11 am

    simple do all the stuff above and open task manager see which program takes most memory get rid of it if you can

  9. Shanawaj Alam
    May 8, 2010 at 6:44 am

    Install Advance System Care, it Will free up ur temporary files and defragment the registry and hard disk, it is a collection of utilities... so please try it.
    for games player there is a option called Game Booster when u on Game Booster ur PC willl run smoothly....

    download it from:


  10. Anonymous
    May 5, 2010 at 11:20 am

    The best way to deal with a slowing PC is to fix it with some powerful registry cleaner and pc optimizer software such as Reginout...

  11. Anonymous
    February 28, 2010 at 1:47 am

    You may want to try Glary Utilities. A free version is available. Does most of the things suggested above and more. Also has some additional tools for checking the infrastructure of you system. Google it and give it a try.

    Also, make sure to check for malware with more than one program. They will all find different things potentially. To be a bit more thorough I always scan with:

    PC Tools (free from Google in the Packages Link)
    Malware Bytes (free version)
    AVG (free version)
    Glary Utilities
    SuperAntivirus (free version)
    Microsoft Defender (free)

    I only have one on autoscan, so they don't fight or conflict (usually AVG since it is relatively low overhead). I use the others on a weekly basis to check for other viruses.

    If you have Vista, in the control panel list there are a bunch of tools you can use to get reports on the performance. Use these to drill down. You can also look at the event log and drill down with it. Any problem event normally has links for more information.

    The other ideas of using the tasks manager or similar tools are great too. Click on the CPU col head to put the most active at the top. I found that an e-card app from American Greeting was using 60% of my CPU that way. Needless to say it was uninstalled when I found that was happening.

    Some quick ides, if they help.

      June 28, 2010 at 5:37 pm

      Just don't install too much antivirus. They can interfere with each other and the background scans use LOTS of system resources. Try to find 1 good antivirus and use it alone.

  12. gkdoda
    February 23, 2010 at 4:20 pm

    You can try number of softwares as mentioned by fellow readers here. But I would recommend that you take backup of your data and install your windows again in separate folder and then delete previous windows folder. I do it after every 5-6 months and it keeps my computer faster and gets rid of unnecessary files.

  13. paul
    February 13, 2010 at 6:58 am

    I used once process explorer from sysinternals to diagnos this.

    Open it and check how much "Interrupts" is using from your CPU. If it's more than 10 while the computer is slow use HD tune (from to read SMART data from the harddrive.
    If you have red lines in there you have hard disk problems.

    I guess you have XP, vista or windows7 can detect and will notify you in case you have hard disk issues.
    If it's vista or windows7 probably you need more RAM, 1gig is not enough, I'd say 2gig can be enough.



  14. Anonymous
    February 2, 2010 at 2:03 pm

    I would go to and run a scan of my PC. Let it tell you what you need to do.

    Your hard drive may be too full also.

  15. Aibek
    February 2, 2010 at 5:41 am

    Check outTop 8 Programs That Can Make Your Computer Run Faster

    the post summarizes:

    - MSConfig
    - CCleaner
    - Revo Uninstaller
    - Defraggler
    - and 5 Best Program Trade-Offs

  16. Francisco
    February 1, 2010 at 7:55 pm

    most computer slowness issues are caused by running multiple applications at one time; that being said, you mention you already have ran an anti-spyware program but it may help to take a look anyway at your add/remove program list and remove any app that would load automatically at start-up; such programs may or may not be detected by anti-spyware; most are those annoying toolbars.

  17. Big Bobo
    February 1, 2010 at 7:26 pm

    What i found interesting is a program called cache set...this is the link for the program at sysinternals .... . Of course all your cache cleanups and defrags and disc cleanups are necessary along with a registry cleaner..but be careful of the registry cleaners..some don't work as advertised and sometimes only slow your computer down..overall its like a regular maintenance you do on ur computer much like you would ur vehicle..

    I hope this was of some help.

  18. Anonymous
    February 1, 2010 at 6:23 pm

    Two tools I use are Autoruns (which tells you which programs start when your system boots up) and Process Explorer (which tells you what's running now).

    Get them both from:

  19. Anonymous
    February 1, 2010 at 5:18 pm

    Don, You did not mention cleaning out your registry, which can be done for free using a program called CCleaner. Also you could type in "msconfig" and look at your startup programs and delete any you do not need. A final suggestion would be to look at how much free space is left on your hard drive. You should have at least 20% free. Good luck, Don

    • aljo
      February 19, 2010 at 4:51 pm

      I worked for months trying every thing that I already new and what I could find
      on the net including this site until I stumbled onto the problem while using
      my computer.



      If I had deleted it and reloaded it might have worked again but in the
      all of the searching I did I read an article from an ex Microsoft software
      employee that their new security program is the identical program
      that they use on their computers and it is free.


      I hope this will do a lot of good for others.
      I'm already on your list.
      Even though you didn't help me, I know you help many thousands.


    • Anonymous
      February 20, 2010 at 8:03 am

      Dear brother's and sister's please keep in your mind that at less 50% free your first partition where your operating system running ... Thanks

    • mysterypoet
      January 25, 2011 at 7:49 am

      yo capitan!! thanks..ccleaner worked for meeeeeeeeeeeeeee

    • Kman
      March 17, 2012 at 4:31 pm

      For me I've tried multiple things from registry cleaners to full software programs that were designed to bring PC speed back up. Not to mention a system restoration with few backed up files on a removable drive. I literally saved less then 4gb of things, a couple were games and none of them were constantly active programs/software that would reduce speed(infact i use one to good benefit).
      Even that did not keep my PC running smooth or performing the way it used to.
      What I discovered recently was that it was incoming/outgoing connections that had no real business coming through/to/out of my computer. Of course over the lifetime of a computer more and more websites( 'reputable' ones even)do get ahold of your IP, and there is nothing that I know of that states they cannot use it if they know it, and so some do. I systematically shut off ports and blocked incoming connections from a multitude of sources that had absolutely no effect on my browsing and gaming connections(the only ones that should have been active) and infact allowed me to increase my bandwidth to those connections. Surprisingly enough, everything on my computer is now working faster, and some problems with handling multiple programs in different windows disappeared. I haven't run into any connection problems so far, and since it was trial and error(block a port, check internet, block a group of IPs, check internet so on so forth) i was able to manage and select connections I knew SHOULD be connecting. I think this may be a very substantial type of situation where PC's might slow down significantly and end up with poorer overall performance and much slower internet speeds on things they are doing. Noted, i tested connection speeds before and after this, they stayed basically the same, but every page, streaming movie etc. loads 2-3x faster...go figure.

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