In the mornings when the laptop is first switched on, everything works fine. But by the end of the working day the laptop is unbearably unresponsive. For example, when typing into MSWord in the morning, it works perfectly. But by the end of the day, when typing into MSWord, I do not see the text appear in MSWord until after about 10 seconds at a time after typing it. So if I am touch typing, I see blocks of words appearing in MSWord every 10 seconds or so.

This seems to happen for all apps on the laptop, not just in MSWord. The above issue happens no matter how many apps I have open at the time, so even if I just have MSWord open, it will still happen.

Laptop specs:

CPU: 4 Core i7-8650U (8th Gen)
SSD: 256GB
OS : Win10Ent64

I have tried looking at the task manager, I can't see anything which might be using 100% of the CPU. I have also removed any unused startup apps to see if that makes any difference but it does not. The only thing I have found which temporarily fixes the problem is a full restart of the OS.

I have also updated the OS to it's current latest (non insider preview) and have all the latest manufacturer drivers, bios updates, and firmware updates installed.

So my question is, how do I go about figuring out the cause of this issue?

  • 2
    First, i would check your temps. Use a software such as RealTemp to check this. If the temperature is high, open the laptop and check that the internals are clean and dust-free. If they aren't, use some compressed air to clean it.
    – NiallUK
    Jun 13, 2019 at 8:05
  • 1
    Another thing to fo is look at swap and disk IO. Also, if you reboot does the problem go away? (memory leak?)
    – davidgo
    Jun 13, 2019 at 9:05
  • @NiallJones, I will try this. However, I don't think it is a dust issue as the laptop is only a month old. However, I do think the laptop might be heating up and causing the cpu to throttle, but need a way to confirm this suspicion. Jun 13, 2019 at 18:25
  • @davidgo, yes a reboot fixes the issue for a few hours. What's the easiest way to see what is causing a lot of swap/disk io activity when the laptop is being very unresponsive? Jun 13, 2019 at 18:26
  • 1
    Sounds like a memory leak to me. Im a Linux person, so not in a position to advise how to check disk IO in Windows - although many laptops have a disk indicator you can use, and I expect the task manager must show swap, memory and CPU usage?
    – davidgo
    Jun 13, 2019 at 19:36

6 Answers 6


The hardware person in me says it's overheating and throttling, but you'd notice if it became noisy or the case was too hot, wouldn't you? Has it always done this? It's always possible the manufacturer forgot to plug in one of the fans, or there's something blocking it. This happened to me with a Dell desktop, the CPU fan was tangled in some power supply wires as delivered from the factory.

The software person in me thinks this is probably a memory leak in a program you don't realize is running, or forgot you installed, which would explain why it's cleared on a reboot. Use Resource Manager to watch your memory usage, and see if you can tell what program is using all your RAM.

Other possibilities include more than one antivirus program (they can fight with each other and slow your machine), malware (run and then remove the free MalwareBytes scanner), or some program going berserk and eating all your CPU (Resource Manager is your friend again) for no particular reason. Open Add/Remove Programs and get rid of anything you don't need or recognize (Google unknown programs to see what they are before removing them).

  • The software person in me agrees with your second statement. This could easily be tested by turning off the laptop when it gets slow, then immediately rebooting and continue using it. If it doesn't get slow until a few hours later, I would first guess a memory leak.
    – DrZoo
    Jun 21, 2019 at 14:26

I like @wpns's answer but to add:

Most likely causes to slow performance:

  1. CPU

If too much CPU is utilized, resources for processes will be scarce. You say that you don't see any process using 100% of CPU but is the CPU 100% in use? Lots of small tasks could collectively eat up the CPU.

Security applications like antivirus are frequently a cause for performance problems. Take note if you have scheduled scans during the times you have issues. Try to schedule scans for periods when you're not using the machine. Some applications allow you to temporarily disable their features which would allow you to confirm if they are the problem. I would take care in doing so, you may wish to disconnect your machine from the internet before disabling security features.

If a CPU gets too hot, it will also deliberately throttle down the performance (at least chips made since around 2002). If the machine is getting warm from the environment, or the fans are not working well, or the heatsinks are clogged with dust, you could be experiencing performance issues from throttling. There are a number of utilities that can read the temperature for the CPU, some BIOS will also report this information. Appropriate temperatures for your machine will vary wildly based on design but I'd say anything above 50-60C would be too hot.

  1. RAM

If a machine doesn't have enough RAM available, it will begin to use more and more Virtual Memory which is when hard drive space is used for memory. Hard drives are much slower than RAM and this will cause the machine to slow. The more RAM is used, the more this will begin to affect your performance. A computer will try to optimize virtual memory to reduce access and put more frequent items on real RAM and less frequent in HD. An access to virtual memory is called a 'hard fault' and the number of them can be seen in the task manager. Higher numbers of hard faults are bad. You should not see the number above 10 in normal operation.

It's worth noting that your computer may seem like it has a lot of RAM available but Win10 uses RAM in 'special' ways. Greater than 75% usage of your system RAM will trigger special conditions on your machine. You can also see the 'real' RAM usage under 'commit' in task manager, the number will often exceed the physical RAM in the system.

As @wpns said, applications frequently have tiny errors that can 'waste' RAM over time. A reboot of the system will usually resolve that issue. If you're experiencing a daily problem, your issue is more severe than average however. Take note if you have this problem more often with certain applications.

  1. Hard Drive

When a hard disk performance falls, this can make virtual memory issues worse. However, a hard disk issue can be bad even when RAM is available. Certain applications and portions of the OS are designed to read from HD under normal conditions. This can cause slow performance if HD performance is bad. A failing HD will often cause very long delays. MS Word will automatically save your working document to recovery every 10 minutes by default. When this occurs, you could see long delays before your system responds if HD performance is bad. Use a utility such as SMART or CrystalDisk to examine the performance of your HD.

  1. Misc.

Extra applications, intentional or unintentional (adware, spyware, malware), can cause 'hidden' delays on your system. Sometimes it's not possible to see an application's impact from task manager. In some cases, the operating system itself can be corrupted and cause problems.

You can diagnose some of these issues by putting your machine into minimal start (using msconfig), safe mode, reinstalling your operating system, or running a temporary live boot cd (knoppix, ubuntu) and seeing if your machine behaves similarly in those modes.

I once had a machine that would refuse to run correctly with Windows installed but ran fine with Ubuntu. I never figured out why and decided it wasn't worth my time since it was just an internet browsing laptop.

Best of luck with your search!


Definitely sounds like it's likely hardware related - here are some things to try:

  1. Check the hardware temperatures with Speccy - everything is important to run under about 60C for optimal performance - some CPUs and Graphics Cards can handle higher temperatures but generally you will STILL get better performance upgrading/configuring/cleaning the cooling to run them lower around 60C or below. They should definitely not idle above 60C. Anything close to 90C or above is risking hardware damage / desoldering parts / definitely slowing down the system for sure.

  2. Firmware / Power cycle - turn it off and remove all externally connected devices, power cable, and laptop battery (if easily accessible) and hold the power button for about 20 seconds. This can help correct fan controls and temp sensors.

  3. Disable CPU Turbo Boost - for older laptop of 4+ years - sometimes the processors begin to run hotter / develop cooling issues (especially with turbo boosting on CPUs). Go to the Windows Power Settings and lower the Maximum Processor Speed to 99% to disable the turbo boosting - ironically this can make systems faster when they aren't overheating from the turbo activation (a subtle temporary overclock basically that really pushes the CPU when needed - not really tested durability after years of use).

  4. Clean the fan / cooling - if easily accessible (or you're familiar with proper disassembly), typically using compressed air on removed fans works best and I don't recommend blowing air directly into the fan grill as this just pushes dust deeper in the laptop usually. Hold the fan still before blowing it, don't let the air spin the fan as it can spin beyond the rpm it's designed for causing damage to the bearings.

  5. Scan drives for integrity issues and bad sectors. With bad sectors, a computer may perform perfectly fine for hours or days and suddenly hit performance issues later after the disk accesses these problem sector areas on the disk platters themselves. Run Windows Check Disk with all scanning options enabled (scan for bad sectors) can help the drive mark these to be ignored and thus relive the bottleneck. Check Disk can fix many other non-hardware related file structure integrity issues that may be causing these performance issues as well. To go further, you can also run HD Tune and check their S.M.A.R.T. statuses and run sector scans on each storage for further diagnosis. Often S.M.A.R.T. reports the age and extent of use on these drives but can also report severe issues that may recommend replacing the drive. A sector scan can bottleneck the system if the drive hits quite a range of bad sectors (10 seconds+ for even the most basic tasks when the disk controllers are struggling with the failing storage). If there's many of them and/or the scan cannot complete (keeps freezing entirely), replacing the storage will be necessary.

  6. To diagnose a potential software issue with the operating system - try running Windows in SAFE MODE by tapping the F8 key during boot and see and select Safe Mode with Networking. Run this for several hours or a day and check if the performance issue has returned. If not, you may have a software issue and need to reinstall the OS.


Given, that the problem occurs after using your computer for several hours and temporarily goes away following a reboot, the most likely cause is a memory leak in some program, that starts automatically, after you boot or log on. A good first step would be to try and disable as many as possible unnecessary programs, that you are aware of starting automatically. A secoind step would be to use ProcesExplorer to check if, and which processes use a lot of memory and/or has a lot of paging/disk IO after running for a long time.

  • This doesn't really add anything to the existing answers. The intention is that each answer provide a solution that hasn't already been contributed. The way to indicate that you think another answer is good is to upvote it (which you will be able to do with a tiny bit more rep).
    – fixer1234
    Jun 22, 2019 at 18:52

OK I'll bite. Interestingly, the one thing that immediately jumped out at me that nobody mentioned is (web) browser. I have always been plagued with issues similar to the ones you describe, and have confirmed definitively that they were caused by my browser. My "daily driver(s)" are Mozilla based, and Mozilla based browsers are notorious for leaking memory like a sieve. It's not entirely Mozilla's fault. They seem to work at plugging all the leaks. But the (compiled) JavaScript that they're forced to load, and run. Can be really poorly written, and be really abusive. This is especially true where advertizing scripts are concerned. Speaking along the lines of advertizing; while I run Windows 8+ on my laptop, and not 10 (as you appear to). My "Home" screen is, by default, running (web) "feeds". If yours does too. This is also a form of (potential) web noise/(potential) abuse -- albeit IE, not (possibly) Mozilla.

In the end. Without some vital information from you, and based upon my own (consistent) experiences over the years. I'm inclined to believe that your "web experiences" are likely to blame. If you can, consider examining the memory eaten over the day by your web browser, as well as the CPU slices/time. This will be easier for a "3rd party" browser, than IE. As IE is part of the OS. But none-the-less. I'd bet you find your browser may well be the culprit.

In fact. You might be able to isolate it by waiting for your Laptop to become swamped. Then kill all your Web based stuff, and see if things don't start returning to something closer to "normal". :)

That's my assertion. :)


Since a restart fixes the issue, it sounds like a software issue as opposed to a hardware issue. You may want to try reinstalling Windows and start from scratch. Be sure to back up your personal data and make a list of all the software you regularly use. Once this is done, you might want to slowly reinstall your programs, one by one, and if the slowdown issue happens again you will know which program is causing it because you will have just installed it.

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