Reasons the app isn't running well on Windows

Are you new to the FLOSS world or simply want to try a new app or a new release of it? Eager and excited, you download it and one of three things happen: it is slow, freezes or crashes. Or it doesn’t open or work as you would expect. You visualized throwing yourself out of the window. Why is the cost of entry so high and immediate?!

This seems to be a prevalent problem among Windows users. I and others have composed many posts in attempt to help the exasperated. I don’t remember all of the causes; you could search the forum for the complete list of relevant posts. Anyway, this thread is meant to keep a list of links and answers for your convenience. Feel free to add anything that you might find useful. I will start the thread with the basics.

As such, this is a work in progress. If you have any thoughts, please comment below.

Windows Defender. This is the biggest offender because it continuously scans everything and, in doing so, literally brings your most powerful computers to their knees. When you open an app that it doesn’t like or loves too much, everything that the app does is assaulted, like enforcement gone wrong at border crossings or a helicopter parent suffocating his or her children.

What to do: turn it off completely to see if it is the culprit. Turning it off is a nauseating process because it has so many components, many of which can turn themselves back on without your permission. There are several ways to go about it correctly. Here is one example: Lastly, you might have heard that it would be disabled if you had another antivirus app or something similar running. That isn’t true all of the time. Defender does what it wants to do.

Look what happens when I extract a zip file. Before and after disabling Defender.


Warning: please turn Windows Defender back on after you finish your analysis because although it is often disruptive its actions are for your safety. Do it as soon as possible as it is easy to forget. What you need to do is Add an exclusion to Windows Security. You may need to do other things but start with this one.

Other Windows culprits that I won’t get into but are worth looking into: indexing, compression, encryption, backup system, file system; and driver, app, acceleration, optimization or hardware incompatibility. There might also be inefficiencies or bugs in the FLOSS app itself, but think about that after you eliminate the common causes first.

Safe mode (with or without networking). Running the app in safe mode is good for two reasons.

1. It insulates the app you want to run from all of the junk that Windows has and that you have accumulated. Basically, it loads the bare necessities so that you could figure out whether the app in question works, and if it doesn’t, you have a shorter list of suspects to work through. Since you are only running the core software, you might need to load additional software such as drivers for your graphics card, etc. But then you know precisely what you are dealing with by means of the process of elimination.

2. The other reason is that it loads the core system files in their default and safe settings. This means that anything that is missing, corrupted or otherwise messed up has a good chance of being restored to a proper working state.


Troubles with a Installer or Package
Some people might find that there is a problem with the installer or package they have just downloaded.

1. Make sure that you have downloaded from a reputable source. Check out the app category of the forum and read the pinned posts, or threads that may give you suggestions. Regular users like myself could direct you to the right places as well. When in doubt, ask.

2. Your antivirus or a similar app might flag the installer, app or DLL as a virus or malware. There are a number of reputable online virus scanners that you could use for free to verify if it is a false positive or not. There are several posts that provide suggestions.

3. After installation or extraction of a portable app, when you run the actual app, you might get a warning like this. Well, if you know that you want to install the app, chances are that it is okay. Many FLOSS apps aren’t registered with Microsoft and affliates. The fact that it is unrecognized doesn’t mean that the app is illegitimate. Click “More info” to get the option that you really deserve: “Run anyway”. Anyway?! Just run it already!




File system. I refrained from elaborating on file system reasons because 1) I am not a fluent in that subject and 2) I didn’t think of a good example from the top of my head. In the comments, @darix provided a link concerning the Windows Subsystem for Linux (WSL) that addresses a part of the picture.


@afre Sorry to nag about this, but I cannot believe your claim that Windows Defender can slow your computer down significantly. My main concern is with the example you provide to prove this. I am left to assume that the point where you switched off Defender during unzipping coincides with the increase in transfer speed. However, an increase in transfer speed can also be caused by unzipping many smaller files versus a few larger files (there is a little overhead to create a file on disk, which is relatively larger for multiple small files compared to a few larger ones).

If you want to claim that Windows Defender slows down unzipping, can you please provide results from a repeated experiment where you show the transfer rates for the entire zip file with Windows Defender on and again but with Windows Defender off?

Also, claiming that unzipping is a good example why your entire machine may come to a grinding halt because of Windows Defender sounds a little overreaching, but I am willing to accept that.

Personally btw, I have never bothered to disable Windows Defender on my machine and do not experience a significant slowdown. Of course that doesn’t mean that there isn’t one. Maybe I’m missing out :stuck_out_tongue:

It definitely slows down my machine in multiple scenarios. One thing you need to know about my writing was that it was fast and loose, and unzipping is a rather tangential problem that I happened to come across and insert at the time of the writing. My apologies for being more anecdotal than scientific.

If I am understanding you correctly, unzipping many smaller files should be quicker. If that is the case, then my experience unzipping this particular package proves that Defender is causing strain on my system, at least on the SSD and CPU. The more files the zip file has and the smaller they are, the slower the copying becomes; the LEDs blink, the fans whirl and the other components vibrate and buzz.

The most important thing to note is that the main process of Defender was at the top of the task manager list. That said, it doesn’t always happen, but when it does, it is quite obvious. In this particular case, the unzipping wasn’t too bad, it just took a very long time, because I have already tamed Defender somewhat but apparently, after a few recent updates, it is a bit fussier now.

To be clear: I don’t advise disabling Defender, as it is beneficial to most users. I would only do it to see if it is the cause of the system slowdown. I should probably add this to the main post!

Thanks for your feedback by the way. Let me know how I could make it more convincing. (I will try to make the illustration clearer and make some comparisons. Again, it is a tangential case, so I wouldn’t want to put too much stock in it.)

In general, I am not the best person to talk about this subject; but I saw the vacuum and Defender being brought up repeatedly, so I decided to start writing about it, hoping that smarter and clearer minds would chip in along the way.

Last thing I would say is that this is a common problem and it isn’t because of user inexperience or ignorance (okay, maybe a wee bit). A brief online search would yield plenty of results including ones on Microsoft’s own forums, to which its staff mostly refrain from being involved (because they either don’t want to acknowledge the problem or they are among the lucky few who don’t encounter it).

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The way this appeared on my screen made me chuckle:


and that’s why many of us run Linux!

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Not everyone has the choice.

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NEVER EVER recommend turning off the virus scanner.

On the technical side … windows file system is much slower as well:

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Absolutely. Just found the way the heading/category info read, taken together. No harm intended, and sorry if it appeared that way.

I was going to write about these things sooner or later. I already talked about the two items implicitly. To the first point, I guess I should have written it in the first time to make sure that I am not misleading the masses. The guide I linked to also has a warning but I should not rely on that.

Thanks for your feedback @darix.

According to many - or all - reliable tests, Microsoft’s integrated antivirus slows the system down more than any other solution. This is why I am using one of the free lightweight programs, that can be further optimized and are still also better security wise.

@Jacal Yeah, the transition from Window 7 to 10 was an eye opener. The system performance suffered a lot in part due to Defender. I noticed the slowdowns, even with a clean and updated copy of Windows 10. And that was after I disabled all of the unnecessary spyware, ads, nagging and useless components. Windows as a service and your friendly OS my foot! Windows 10 was marketed to use less system resources and to be much faster than Window 7… sigh.

Just to mention, Windows 7 “support” ends with the end of this year. The free transition to Windows 10 is still available. It might be better than nothing.
I have had my PC and my laptop in dual-boot mode for over a year, to learn, what is still missing for a Linux-only approach. (Some games only, actually. I don’t do games any more, but would still like to keep the gamer status. We, the gamers, are young badass people.)
Dual-boot means more work to maintain the “systems”, so I am back on Windows-only. (Linux on virtual machines, though.)
The next PC will be build for Linux, but it is hard to declare an old machine obsolete nowadays. After some upgrades, like a SSD system disk and a better graphic card, the old rig works fine. Even with Win10 installed on top of Win7.
(A clean Win10 installation will probably make the system even more sleek.)

At one point, virtualisation was good but now it takes too much work and resources. Yes, a clean installation is much better. Dual boot is not to my taste because I love to multitask. When I boot into one OS, I feel like I have a ghost limb.

@Jacal May I ask which free AV are you using?

Avast, I’m used to it. With some features disabled (“cybercapture”, “hardened mode”, browser plugin). Avira usually also offers decent protection with small impact on system, but I see it didn’t do well on the last performance test.

personally I dont have much of a problem with defender.

Me neither, on the other hand I have had issues with other AV products, both gratis and paid for.

I have been intending to migrate to Linux for a long time now, however, I have so few issues with Windows that it’s difficult to get motivated to make the switch.

There is at least one technical reason, why some applications performe worse on Windows than on Linux. This can have a significat impact on speed especially if small functions are not inlined:

Linux allows more registers to be used to transfer values on function calls than Windows (see here for reference):


In the defense of defender no issues here either. Chrome is quite a RAM hog though.

This said, my home PC has 8Gb, that can get a bit tight. Office PC has 16Gb and feels faster (almost identical hardware).

Darktable is still fast though, even with my poor quality scans in 16bit TIFF that have about 130Mb.

Going 16Gb RAM would make sense but I hesitate to invest money in 3 year old hardware (strangely, my notebook, i5 8gen, 8Gb doesn’t feel faster)

Looks like it isn’t Defender’s fault after all or the exceptions worked. Here is the latest unzipping screenshot just before its completion. As you can see, it starts off at a snails pace. I have come to accept this and do something else while it is decompressing.


I think another good place to check (that is, if this hasn’t been mentioned yet) is the Internet Options…for instance, I just realized I didn’t have gimp on the trusted sites page!! (very important!)

It is an already downloaded file though…