In Windows 10, there are several ways to prevent the download of files from the Internet. Each method will depend on the browser you usually use. Below, we show you the detailed process for each of the most common browsers.
Blocking downloads in Internet Explorer
To block downloads in Internet Explorer, we must use the Internet options. Access them by searching for Internet options.

Then, under the Security tab, click on Custom Level.

In the pop-up window, locate the Downloads section and disable all options.

Save the changes to take effect. From that moment on, Internet Explorer will no longer have permission to download files.
Block downloads in Google Chrome
To block downloads in Google Chrome, do the following. Open the registry editor by searching for regedit.

Then, go to the path Computer\HKEY_CURRENT_USER\Software\Google\Chrome. If it does not exist, you must create it. To do this, right-click on Policies, go to New and click on Key. First, create the Google key, and following the same method, create the Chrome key.

The result should be what you see in the next screenshot.

Create a DWORD value (32 bits) by right-clicking. The new value should be called DownloadRestrictions.

Double click on it and change its value to 3.

Restart the browser to apply the changes. From that moment on, Google Chrome will no longer download to your computer.
Blocking downloads in Firefox
In the case of Firefox, you must use an extension called Public fox.
Once activated, go to your settings, in the Firefox extensions area.

It is time to specify what type of files should be locked. Also, you can set a password to prevent anyone from making changes to these settings and to let each file be downloaded individually

When you save your changes, Firefox will no longer automatically download the formats you have specified.
Blocking downloads on Microsoft Edge
In the case of the new Chromium-based Microsoft Edge, you can block downloads using the same procedure in Google Chrome. However, the new registry value must be created in the path Computer\HKEY_CURRENT_USER\Software\Microsoft\Edge. If it does not exist, you can create it in the same way that we indicated in the section of Google Chrome. In the following image, you can see the result.

Similarly, by doing this, Microsoft Edge will not be able to download any files from the Internet.