What is the fastest way to select the even files in a Windows folder?

Yes, this is possible (albeit hacky) if your files are named as you describe you can size the File Explorer Window to organise your files into columns (as long as you don't miss any files out so the 'second column' is always even). What you can then do is select every other file, depending on where you start drag and drop (and thus selecting odd or even).

If you View by icon (I chose large icon) and change the width of Windows Explorer so it only has "2 columns" , then you can hold down CTRL and use left click and drag with the mouse, downwards (from just above the first icon in the "second column" (in the white space)).

As an aside, depending on how many columns you have, you could also select every third file or fourth file etc

I've just done it, and it will automatically scroll as well.

You can even then maximise Windows Explorer (File Explorer) and the selection will kept.

The window resizing trick shared by Dave works great for the majority of cases. In my case, I had over 25,000 images extracted from a video and I needed every other image deleted. Waiting for the drag to select all the files took longer than I was willing to wait!

My files were named in the same pattern as yours (file0001.jpg, file0002.jpg, etc). Since I wanted every other file, I knew the files I wanted would either end in a 0,2,4,6, or 8.

To select the relevant files, I entered *0.jpg OR *2.jpg OR *4.jpg OR *6.jpg OR *8.jpg in the search box of windows explorer while I was in the folder with all my images. I then pressed Ctrl+A to select all, then hit delete and I was done!

This trick will only work to select every x numbered items where x is a factor of 10 (so 1,2,5, or 10) but the click and drag should work for any interval.

So this method is fastest but the click and drag method is more flexible. Choose whichever one best suits your needs.