I do have my website, which is around 3 years old, the website is having almost 500 to 600 pages, I do want to customize 404 error pages.
You can use text editor Notepad for writing this file, and save the file as:
“.htaccess” (including the quotes). If you are not able to save this file you can save it with the name htaccess.txt and then upload it to the server. Once you have uploaded the file you can then rename it using an FTP program.