Troubleshooting Slowness, Unresponsiveness, or Freezing during TestOut Lab Simulations (Expanded Edition)

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This article is focused toward troubleshooting TestOut Lab Simulations. See this article for troubleshooting TestOut Videos.


1. Quick Troubleshooting Ideas

If you are facing slowness, unresponsiveness, or freezing while working within TestOut’s Lab simulations, try these things first:

• Restart your computer (and reset your router if you can)

• Close any other programs and browser tabs that don’t need to be running

• Clear your browser cache and cookies -

• Try the labs in a different browser, because the browsers can perform very differently

• If a certain task always freezes, try doing it in the exact way taught in the Hint, Show Me, or Explanation found in the lab report shown after clicking Done

2. Recommended Technical Specifications

TestOut’s labs can be complex and resource intensive. If you still face issues after trying those basic troubleshooting ideas, your computer specifications might not be adequate to smoothly run the TestOut software. Please ensure that you at least meet these recommended specifications.

Note regarding the processor: The CPU should be a High-Mid range processor such as those listed or any other CPU whose average benchmark score from meets or exceeds 3500.
Having an adequate CPU which is not being overburdened is the single most important factor to having a smooth experience in LabSim.

If you don’t meet these recommended specifications, you should try the labs on a faster computer and internet connection, if available, to see if performance improves. If you meet these specifications and still are having issues with slowness, unresponsiveness or freezing, please see this article.

If you don’t meet these recommended specifications, you should try the labs on a faster computer and internet connection, if available, to see if performance improves. If you do meet these specifications and still have issues after trying the ideas in Section 1, then you should try some of the advanced troubleshooting ideas in section 7.

3. How the Labs Work

A common misconception is that everything you do on the internet is all processed over the internet and that its responsiveness depends entirely on the website and its servers. This is not the case. When a student clicks Start Lab in LabSim, the browser requests the necessary files to run the lab from These files are downloaded and then temporarily stored and run by your computer. Once the loading bar disappears, the LabSim simulator uses very little internet and the responsibility to run the simulation falls upon your CPU, RAM, and browser. Depending on how fast your computer can process the information, your experience can vary greatly in terms of loading times, responsiveness, and overall time needed to complete the lab. The single greatest factor in lab speed and responsiveness is the CPU.

4. The Importance of the CPU

Not all CPUs are created equally. Depending on the quality and efficiency of your CPU, your computer might process the actions you take in the lab quickly, slowly, or it could get overwhelmed and become unresponsive.

The graph below shows the number of seconds it takes to complete an average lab based on the benchmark score of the CPU as found on
The same person doing the same lab on the computer with the best CPU took only 146 seconds, while it took 1.85 times as long, 270 seconds, on the computer with the worst CPU. That is all after the lab is done with its initial loading, using the same internet, the same browser, and the same operating system. The CPU you have makes a HUGE difference in the experience you have while working in our labs.

We use a CPU benchmark score as a measurement that corresponds with the speed in which a lab can be completed. We have found that the clock speed (represented by GHz) advertised by CPUs may not accurately measure how it will perform with our product, but a third-party website called has run thousands of CPUs through their own benchmark testing and assigned average scores to these CPUs. These benchmark scores correlate more precisely to the results that we have documented than any other measurement we have come across. We recommend anything as fast or faster than the AMD A12-9720P with its score of 3532. Processors that do not meet the recommended speed may still work, but slowness may be a common occurrence.


Recommended CPU Benchmark score ≥ 3500

See for a list of comparable processors.


What does this mean for you? If you are struggling with slowness and unresponsiveness in LabSim, find out the name of your CPU and search for it on If the average score of your CPU is below 3500, then you may want to experiment on a computer with a CPU that meets or exceeds this recommended score.

If you find that your CPU is adequate, but you are still experiencing unreasonable levels of slowness, unresponsiveness, or freezing, try the troubleshooting ideas found in sections 1 and 7 of this article.

5. How to Find your Computer Specifications

On a Windows computer, we recommend going to the System Information utility. In Windows 8 and 10 you can simply click the Windows icon in the bottom left corner of the screen and start typing, “System information” and then just select it. In Windows 7 you can run the msinfo32 command by holding down the Windows key on the keyboard, pressing the “R” key, and then typing msinfo32 and hitting enter. The information you are looking for is highlighted in the image below.

On a Mac, basic system information can be found by clicking the Apple menu and then clicking “About this Mac”. To find the actual name of your CPU on a Mac, follow the steps outlined here: 

6. How to Find your Internet Speed

To check internet speeds, we recommend freshly restarting the computer, resetting your router, and turning off any other devices that use your internet connection to reduce the possibility of interfering factors. Then navigate to (chosen for its simplicity and acceptable accuracy).

Labs require an internet speed of 3.6 Mbps per user to have good loading times. After initial loading is completed, the lab uses very little internet, although it is crucially important to maintain an internet connection. (Do not close your laptop or put it to sleep during a lab or your results may not communicate properly to our server.) will automatically begin to run its test and tell you your download speed. If you suspect the result you see is inaccurate, reload the test once or twice. If you see Kbps instead of Mbps then your internet speed is inadequate. 1000 Kbps = 1 Mbps. If you find that you are below the minimum internet speed, see section 7.5 for more ideas.

7. Advanced Troubleshooting Ideas

1. Close any programs that don’t need to be running. Some programs and browser extensions, add-ons, toolbars, or plugins can slow you down and eat up your computer’s resources. Others automatically start in the background when you start your computer. Before you restart your computer, try turning off some of the programs that don’t need to start with your computer or browser. This will free up the computer’s resources to focus on TestOut. Consider doing the following things (Google how to do them if you don’t know):

Disable unneeded start up programs

Helpful article:

Disable unneeded browser extensions, add-ons, toolbars, or plugins (keep Microsoft Silverlight)

Helpful Article:

2. Malware can affect your experience with our software. Look through your list of programs and browser extensions. Look for tool bars that you didn’t intentionally install and other items. Pay attention to whether you get redirected to different sites than you entered or if pop-up windows constantly come up. If you notice anything out of place, consider removing it and running a malware scan and cleanup. We recommend the free version of MalwareBytes to help find and remove malicious programs on your computer. (

3. Sometimes third-party antivirus, security software, or firewalls can interfere with They can slow everything down, block certain items from displaying or opening in our program, or even cause the program to crash. Experiment by temporarily disabling these services to see if they might be the cause of your issues in TestOut courseware. If performance improves, consider whitelisting, switching to a different program, or uninstalling that program and using your computer’s default antivirus and firewall software.

One program to note is Kaspersky. Kaspersky has a setting that is incompatible with our software. This setting injects its script into our script, causing hundreds of consecutive errors until the browser crashes or freezes.

Disable this setting: Kaspersky settings>Additional>Network>Traffic Processing: Inject script into web traffic to interact with web pages

4. If you are on a laptop, plug it in. Laptops may not focus on performance if they are set to conserve battery life.

5. If you find that your internet speed is below our minimum requirements and the initial lab loading times are overly long:

a. Contact your internet service provider (ISP) and ask what speed you are paying for. If you are paying for speeds that exceed 3.6 Mbps, but your results indicate that you are receiving considerably less than that, then you should ask your ISP to help you troubleshoot the issue further.

b. If you are paying for an internet speed that is slower than 3.6 Mbps, then consider upgrading your Internet plan or using a faster internet connection at another location, such as at a public hotspot, your school, or the public library.

c. Do what you can on your end. Limit the number of devices that are connected to the internet, try connecting your computer directly to the router with an Ethernet cord, or test on another computer and/or internet connection.

6. If performance only recently got worse, consider undoing recent changes that might have been made on the computer. This would, in theory, reverse an issue that resulted in performance loss. Uninstalling updates, uninstalling software applications (Programs and Features), and restoring your computer to an earlier point (Windows Recovery) are examples of undoing recent changes.

If none of this has helped, try using another computer/network, factory resetting or re-imaging your computer, or contacting TestOut Technical support. You can email us at, call us at 1-800-877-4889, or use the Live Chat function. We are open between 6:00am and 6:00pm Mountain time, Monday – Friday.

8. What to do if your Lab becomes Unresponsive/Frozen

1. Try waiting a minute or two without clicking or typing anything. Responsiveness might return.
2. Try resetting the lab or task with the Reset or Reset Task buttons
3. Close the browser tab labelled, “Simulation Viewer”, and then try loading lab again.
4. If you are in an exam scheduled by your instructor or in a certification exam, try the above steps and note down the question number on which the freezing occurred. You can contact TestOut support by chat, phone, or email and we can reset that question for you if needed, even after the exam is over.
5. Close the browser and try the things in Section 1, Quick Troubleshooting ideas, and Section 7, Advanced Troubleshooting Ideas.



Contact us for additional support, if needed, at 1-800-877-4889. We are open between 6:00am and 6:00pm Mountain time, Monday - Friday.