Confusion , how to create unique files on Laptop?

1. Convert your pdf to images from this site pdf to Image and download zip file.
2. Extract the zip file downloaded.
3. Ctrl+A to select all the image files.
4. Right click on any file(as all files are selected) and select rename.
5. Give any name to the file, it will create file name with the unique index on every file. As an example: You gave "hello" it will create "hello (1)" itself.
6. You have 10 files then, it will be named as "hello (1)" ...........up to "hello (10)".
7. Click the browse/choose files button below.