Some Windows 10 users are reporting that they are unable to install any plugins on their Notepad++ installation. There are several different error messages associated with this issue, but the most common one is “Installation Error: Installation of Compare failed.”
After investigating this particular issue thoroughly, it turns out that there are several different underlying causes that might end up triggering this type of error with Notepad++. Here’s a list of potential culprits that might be causing this problem:
- Missing admin privileges – One of the most common situations that will spawn this issue with Notepad++ is a situation in which the application doesn’t have enough privileges to allow the modifications of existing files. As it’s been confirmed by a lot of affected users, you can resolve this problem by forcing admin access to the launcher.
- The plugin cannot be installed conventionally – If you’re attempting to install a plugin via an external managed, chances are it’s failing because it’s not compatible with sideloading. In this case, you can attempt to install the plugin via the Plugin Manager module inside Notepad++.
- Required Transport Layer Security is Disabled – Keep in mind that if you are seeing this error while attempting to install a legacy plugin, chances you are missing a key transport layer security feature required by the plugin. To fix this issue in this case, you’ll need to enable the required TLS technology from the Advanced Settings menu of Internet Options.
- Outdated Notepad++ version – As it turns out, you can also expect to see this particular issue occurring in those situations where you’re using a severely outdated Notepad++ version that’s not compatible with Windows 10. In this case, you should be able to fix the problem by installing the newest version of Notepad++.
- Plugin Manager Plugin is busted – Under certain circumstances, you can expect to see this issue occurring due to an issue with the Plugin Manager feature included with Notepad++. In this case, you can avoid the error by sideloading the plugins that you want to install.
Now that you are acutely aware of every scenario that might end up causing this particular issue, here’s a list of verified methods that other affected users have effectively used to get to the bottom of this problem:
Method 1: Running Notepad++ as Administrator
As it turns out, one of the most common issues that might trigger this particular error code is an instance in which the Notepad++ application doesn’t have enough permissions to manage the installation of new plugins.
As recommended by the official documentation, Notepad++ needs admin access in order to perform tasks that include modifying the original installation (the installation of new plugins falls into this category).
Depending on your UAC (User Account Settings), you can expect to see this issue occurring in instances where the Notepad++ application didn’t receive admin access.
If you find this scenario to be applicable, follow the instructions below to force OS to open Notepad++ with admin access and modify future launches of the app to open with admin access:
- Right-click on the Notepad++ shortcut that you use to launch the game and click on Run as administrator from the context menu that just appeared.
- When you’re prompted by the UAC (User Account Control), click Yes to grant admin access.
- Once you’ve ensured that you have opened Notepad++ with admin access, attempt to install the plugins once again and see if the issue is now fixed.
In case you still end up seeing the same “Installation Error: Installation of Compare failed.”, move down to the next potential fix below.
Method 2: Installing the plugin via Plugin Manager
More often than not, this particular issue is reported to occur in instances where users attempt to install plugins manually or using an external module. This might cause issues on older Notepad++ installations, especially on windows 10 where the security protocols are stricter.
If you find yourself in this scenario, follow the instructions below to use the Plugin Manager to install the Notepad++ plugin that was previously failing to install:
Note: This method assumes that you are already using the latest version of Notepad++ and you have no remnant files that might be interfering with the operation. If that’s not the case, move down to Method 3 and follow that first before following the instructions below.
- Open up the Notepad++ application and use the ribbon menu at the top to click on Plugins, then click on Plugins Admin from the context menu that just appeared.
- Once you’re inside the Plugins Admin menu, select the Available menu from the ribbon bar at the top, then use the search function to find the plugin that you want to install.
- Once you manage to successfully identify every plugin that you want to install, check the box associated with each of them, then click the Install button to begin the installation.
- At the confirmation prompt, click Yes and wait for Notepad++ to restart and the plugin to be installed.
- When prompted by the UAC (User Account Control), click Yes to grant admin access, then wait for the operation to complete.
In case this attempt at installing plugins results in the same “Installation Error: Installation of Compare failed.”, move down to the next potential fix below.
Method 3: Enabling TLS 1.0, TLS 1.1, and TLS 1.2
If you’re encountering this issue while attempting to use the Plugin Manager of Notepad++ to install plugins, it’s also possible that the operation fails because a Transport Layer Security (TLS) technology that is not active on your computer but it’s required by the Notepad++ plugin.
In this case, you should be able to fix the problem by accessing the Internet Options screen and enabling TLS 1.0, TLS 1.1, and TLS 1.2 from the Advanced settings menu.
If this scenario is compatible with your current situation, follow the instructions below to ensure that you enable every transport layer security that might cause this problem:
- Press Windows key + R to open up a Run dialog box. Next, type ‘control’ in the text box, then press Enter to open up the classic Control Panel interface. When you’re prompted by the UAC (User Account Control), click Yes to grant admin access.
- Once you’re inside the classic Control Panel interface, use the search function (top-right section of the screen) to search for ‘internet options’. From the list of results, click on Internet Options.
- Inside the Internet Options menu, click on the Advanced menu from the horizontal menu at the top. Once inside, scroll down through the list of Settings until you reach the Security category.
- Inside the Security tab, ensure that the boxes associated with Use TLS 1.0, Use TLS 1.1, and Use TLS 1.2 are all enabled before clicking on Apply to save the changes.
- Once you manage to save the changes, return to the Notepad++ and attempt to install the plugins again to see if the problem is now fixed.
In case the same problem is still occurring, move down to the next potential fix below.
Method 4: Install the Latest Version of Notepad++
According to some affected users, you can also expect to see this error code occurring in situations where you’re actually attempting to use an older version of Notepad++ that’s not fully compatible with the latest security updates on Windows 10.
Several affected users that were previously dealing with the same kind of issues have reported that they managed to fix the “Installation Error: Installation of Compare failed.” by uninstalling the current Notepad++ version, and eliminating any remnant files before installing the latest available version compatible with Windows 10 again:
- Press Windows key + R to open up a Run dialog box. Next, type ‘appwiz.cpl’ inside the text box and press Enter to open up the Programs and Features menu. If you’re prompted by the UAC (User Account Control), click Yes to grant admin access.
- Once you’re inside the Program and Features menu, scroll down through the list of installed applications and locate the entry associated with Notepad++. From the context menu that just appeared, click on Uninstall from the context menu that just appeared.
- Next, open File Explorer and navigate to the following location and remove any remnant files leftover from the old installation of Notepad++ before restarting your computer:
- After your computer restart is complete, open your default browser, visit the download page of Notepad++ and click on the Download button associated with the latest version of Notepad++.
- Once the installation executable is successfully downloaded, right-click on it and choose Run as Administrator from the context menu that just appeared.
- Inside the installation screen, follow the on-screen prompts to complete the installation before finally restarting your computer once again.
- Once the next startup is complete, launch the recently installed version of Notepad++ and see if the problem is finally fixed.
If this problem is still not resolved, move down to the final fix below.
Method 5: Installing the Notepad++ Plugin Manually
If none of the methods above have worked in your case, you can also try to install the failing plugin manually, pasting it into the correct location and then importing it into the main Notepad++ application.
This method was confirmed to be effective by a lot of users that we’re encountering the “Installation Error: Installation of Compare failed.” while attempting to install an older plugin.
If this scenario is applicable, follow the instructions below to manually download the updated list of Notepad++ plugins from Sourceforge and then sideloading the failing plugin into Notepad++:
- Ensure that Notepad++ is completely closed and not running in the background.
- Visit the download page of Notepad++ Plugins from your favorite browser and click the Download button to begin the installation of the plugins.
- Once the download is complete, extract the contents of the archive you’ve just downloaded to the following location:
- Next, open Notepad++ and click on Settings entry from the ribbon bar at the top. Next, from the context menu that just appeared, click on Import > Import Plugins, then pick from the list of plugins the ones you want to sideload.
- Next, Notepad++ should show the restart message – If you see it, restart as instructed, then you should see the new plugin appearing inside the application.