The contents of your file should look similar to this, but of course with your own websites:
You can add as many URLs as you want. Just make sure each line starts with 'start'.
If you save your file in the usual way, it's just a 'harmless' Notepad file. Instead, you have to save the file as .bat. Note, don't use Save as, but you must manually add the .bat extension to the file name.
For example, you could name your file TechSites.bat.
You can leave the file type as Text Documents. Click Save and all are done. You can save the file in a location other than your desktop, but for easier access, most people choose to save the file right on the desktop.
Once the file is saved, you can double-click the file at any time to open all the webpages in the list at once. If you receive an error message, check your file to make sure any website URL is entered correctly. To avoid the problem, open each website in your browser and copy that website URL into your .bat file.
Although you can open multiple websites in Windows 10 at the same time with this Bat file, if the needs change over time, you may need to add or remove several websites from the list.
You don't need to retype everything, just right-click on your file, and choose Edit. This will reopen the file in Notepad for you to edit. Save your changes when done.
Sometimes the file reverted back to .txt. In this case, reopen the file and save it using the same procedure as when you created the file above.