Unfortunately by default, the LINQ to SQL Classes doesn't get installed but there is an absolute and easy way to add this feature later as:
- Open Visual Studio 2017/2019 and Go to Tools > Get Tools and Features… It will ask permission for User Access Control. Click Continue.
- Click on Individual Components tab and then search for LINQ to SQL tools and click on Modify button:
- You will see the progress in next windows and when it finished, this tool can be found in Add New Item.
- Now go to Add New Item section, and you will be able to add LINQ to SQL Classes in your project.