I have a relatively new (under 2 yrs old) Windows 7 machine. It has 9GB of RAM, and an i7 core CPU (930 @ 2.8GHz w/ 8 CPUs). After about 8 months since a clean install, I noticed my computer was running slowly. I figure it was fragmentation etc, and I did a complete wipe & clean reinstall.

However, my problems are somehow persisting. The computer is running painfully slowly (but in leaps and bounds - sometimes it will work fine for 3 hrs, then suddenly freeze up just from clicking the start button). The 'freezes' happen randomly - not during any especially intensive computing. I initially thought something might be eating through my CPU and/or Memory, but Task Manager indicates that neither the CPU or Memory spike. In fact, even during serious lag, CPU usage remains at less than 5% and Memory at ~ 1.5GB.

It's beyond me why a fresh install on a powerful machine is performing so poorly. And it certainly is frustrating! What could be causing the poor performance, and what can I do to fix it?

  • 4
    random freezes point to hardware failure, most likely ram. i also think your "it runs slow because of defragmentation" was a wrong conclusion, defragmentation is not really a problem under win7. check your hw.
    – akira
    May 22, 2012 at 6:01
  • is this happening after you reinstall your OS?
    – Alfred
    May 22, 2012 at 7:08
  • Does this serious lag also happen when in safe mode? May 22, 2012 at 9:33
  • You can also use a tool like HDTune to examine the performance over the full length of the disk. You are looking for large dips, or a very erratic line which would indicate you either have a poor quality or dying HDD. The kinds of numbers to expect for a single 7400RPM drive would be ~80-130MB/s read and ~10-15ms access time, if you've got RAID or an SSD then its a whole other kettle of fish (and a different set of trouble shooting).
    – Turix
    May 22, 2012 at 10:02
  • Be sure to run the tests DURING slow moments - they won't help if they seem to run normally since you would not know which device is not performing optimally.
    – netrox
    May 23, 2012 at 16:27

6 Answers 6


It seems like it could be the hard drive dying, which would slow windows down.

  • 1
    How do I confirm this diagnosis? If this is in fact the case, a assume I will need to purchase & install a new HD?
    – arcologies
    May 22, 2012 at 4:43
  • Ok, thanks. I'll get back to you once the check is completed...
    – arcologies
    May 22, 2012 at 4:49
  • Also worth monitoring the HDD light and/or the resource monitor (open task manager, go over to performance, click on resource monitor, go over to disk tab). Also, the standard troubleshooting advice: find all of the most updated drivers you can and use those (incl motherboard, gpu, any peripherals, etc) Also, quibbling over semantics, you have four hyperthreaded CPUs. There is a difference.
    – Ross Aiken
    May 22, 2012 at 5:31
  • After switching hard drives for my boot drive, it turned out that my boot drive was VERY slow. Because this is where I had my important stuff (programs and whatnot) it had some pretty nasty effects. I just shuffled my HDs and everything was better.
    – arcologies
    Nov 28, 2012 at 7:28
  • 2
    I have the same problem, but I'm pretty sure it's not hardware related seeing as there's absolutely no problem in Linux.
    – RobinJ
    Aug 23, 2013 at 11:45

These symptoms sound like a CPU throttling issue that I had. When my laptop overheated, the CPU would reduce its speed (throttle back) to reduce heat output... as a result my CPU % appeared to be low at around 15%, but in fact the CPU had cycled back to 16% of its max and so it was in fact running flat out.

You can diagnose this by using Resource Monitor instead of Task Manager. (Type "resmon" into the Start-Run prompt.) At the top of the CPU tab processes window there is a useful "Maximum frequency" which will reduce as the CPU throttles back.

If this is the problem then you can look at causes of the throttling. You can use free tools like Speedfan to monitor temperature and check on your fans.

In my case there was a definite correlation between throttling and temperature. My laptop was a Dell E6400 and I used a fan assisted cooling tray to assist with the overheating, and I also hit a known issue with this laptop model - see http://www.xtremesystems.org/forums/showthread.php?240717-Dell-Latitude-E6500-E6400-ThrottleGate-Fix

  • 2
    Thanks for this info. This led me to check out my power plan, which was set to a plan that reduces my computer's performance. Switching to the High performance plan, gave me full CPU power again. I was considering buying a new laptop because of this issue, so this saved me lots of cash! Thanks!
    – Bertvan
    Sep 13, 2014 at 11:59
  • Cool. I can't believe I hadn't heard of resmon before!
    – Ryan
    Sep 24, 2015 at 0:29
  • I had same "Maximum Frequency" problem, it stuck on 29%, and my Power plan was on "High performance". Turned out cpu's fan was dead and laptop turned CPU throttling on to safe cpu from overhitting
    – YMC
    Dec 28, 2016 at 21:34

This might be caused by the selected Power Plan. The "Balanced" power plan recommended by Windows is not very clever and can affect the performance badly (50% in my case).

So: check the Maximum Frequency in the Resource Monitor, like SteveW explained. If the Maximum Frequency is not 100% check the Power Plan (battery icon in your tray bar).

Set the Power Plan to High Performance. If it solves the problem then you can start playing around with other plans or configurations but at least you have identified the issue.

  • An answer from three years ago has already been accepted.
    – suspectus
    Aug 5, 2015 at 8:21
  • 5
    ...but, @suspectus, Stack Exchange Q&As are also (or: above all) meant to be archives for future visitors who have the same problem? The more possible solutions the better then, I'd say, and this seems to have been the solution for Fernando.
    – Arjan
    Aug 5, 2015 at 8:55

1) Run Windows Memory Test: Start->Control Panel->type "memory"->Diagnose your computer's memory problems. That will run the Windows memory diagnostic and it's a good place to start.

2) Run Command Prompt as administrator and then type "chkdsk /r" and hit enter. Follow instructions. That will check the integrity of your install.

If you had extra RAM lying around you could easily switch that out and see if it helped. It's possible that your video card is maybe acting up but that's just me trying to think of all the conceivable issues.


IF you generate these two log files and post it somewhere for me, I can tell you exactly why it runs slow. Some will be high probability, background indexing or security scans, others may be rogues. http://www.geekstogo.com/2010/05/27/otl-by-oldtimer-a-modern-replacement-for-hijackthis/ I've done this hundreds of times so I can read these logs.. Not for the newbie to analyze, but anyone can run it. ITs called OTL.exe


My usual findings are excessive slugware or good programs when used in combinations of certain others, make a quad core tower into a dinosaur at times. One of the biggest slugs can be in some cases, using >1MB host files which are readin periodically into separate memory caches by EVERY active app. that uses web for updates or has firewall privvies. This in combination with the File INdex service plus a massive AV solution with a 4 or more services. I have solutions to all of these and hundreds of more reasons why OTL.exe can tell me exactly what is slowing down your PC. BTW. The Task mgr only records a snapshot of CPU useage every 15ms and apps which run short threads and exit or use hidden features or consume a lot of hidden time in maintenance are not recorded in Task Mgr. Hence 2%cpu usage means nothing. There are better tools , procmon.exe , Mark Russinovich® free tool, being one, to see what is happening. I digress but can prove what I promise.

I will reply with a list of suggestions and recommendations for you to fix your own PC and learn why / what/ how to make and keep it screaming fast and stay secure.

Disk errors can easily be found in the System log file. BLoated or corrupt MFT's or backup $mft files can be bloated or corrupt can contribute to delays and remedied with run> chkdsk /f (y on reboot). But none of these are sufficient to explain your symptoms on their own.

Msconfig.exe is a primitive tool that just scratches the surface and does not show hidden files, processes, services or rogue drivers, rootkit, or bootkits.

THe choice is yours. Trial and error or get help from a Windows expert.(moi)

Update 5/25 Having reviewed your OTL.exe log files, the results have raised a few questions in my mind, but still no certainty to actual random system stalls at your end. I can indicate few high probability areas of high risk. Further feedback from you on when this starte and how often it occurs will help me.

Generally, you have evidence of reasonable security and evidence of common insecurities.

Security minded Apps

  • Microsoft Security Client
  • Windows Defender
  • Avast
  • SpyBot
  • PeerBlock

Unknown traffic load

  • LogMeIn
  • FileZilla FTP
  • PowerIso
  • Dropbox
  • uTorrent

There are a few other startups that may be sluggish but.... since this was a clean install of Win7x64 on May 13th, when did it behave acceptable last ?


This is in response to OTL.exe log in support of previous answer. (need more than 600 char) So it is an extended answer.

  1. Routine - update spybot at your leisure
    http://www.safer-networking.org/en/mirrors/index.html for your lang.

    • spybot - search & destroy\DelZip179.dll" on line 8. The value "*" of attribute "language" in element "assemblyIdentity" is invalid.
    • send above to detections(at)spybot.info ( Spybot tech ) if update repeats error. They will resolve. (common issue)
  2. Urgent - Real-Time Protection feature has encountered an error and failed.

Microsoft Antimalware | ID = 2001 , ... has encountered an error trying to update signatures, Current Engine Version: 1.1.8304.0 Previous: 1.1.8403.0 , Another version of this product is already installed. Installation of this version cannot continue. To configure or remove the existing version of this product, use Add/Remove Programs on the Control Panel.

If that fails (See Event Viewer) call MS (free security support 800-xxx) and resolve.

These are just results not the cause of your issue. OTL.exe generates two log files. I need the other to figure the cause. Most likely infect App installed and need combofix.exe from Bleepingcomputer.com to clean. Will advise later, when you send 2nd log from OTL.exe. Best advice is stay in safe mode or dont run.


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