Help : Creating thumbnails please.

[Bertie Doe]

I'd like to create the thumbnails that most CC posters use. i.e. those who post a cluster of say, 6 thumbnails, where you can click to enlarge.

 

I've got a newish Dell, which is preloaded with Windows 10. W10 seems more complex than the W7 installed in my old Dell. My browsers are IE and/or Firefox.

 

I'm long retired and none too techie. Any leads would be appreciated, regards Paul.