Final answer:
To disable .aspx being added to all URLs generated from Sitecore, modify the Sitecore configuration file and update the LinkManager.Configuration setting. Set the alwaysIncludeServerUrl attribute to false.
Step-by-step explanation:
To disable .aspx being added to all URLs that are generated from Sitecore, you can modify the Sitecore configuration file. Specifically, you need to update the LinkManager.Configuration setting and set the alwaysIncludeServerUrl attribute to false.
Here is an example of how to modify the configuration file:
<setting name="LinkManager" value="Sitecore.Links.LinkManager, Sitecore.Kernel" />
<setting name="LinkManager.AlwaysIncludeServerUrl" value="false" />
<setting name="LinkManager.ShortenUrls" value="true" />