Help with the command line parameters (total noob)

[NusNus]

I´m building a digital photoframe from an old laptop. I´m using win98 as the operating system because it´s an old computer and i don´t know how to use linux.
My problem is that I can´t get the computer to automtically resize and move images.

Here´s my question: How should the command line look like if NConvert would:

- Resize all images in folder A, including subfolders, to 800x600 JPG
- Put the resized images into folder B
- Delete the original images/all contents in directory A
- Then when the computer boots up again it does the same if there´s any pictures in folder A. Otherwise do nothing

I´m asking you this because I really suck at coding. I have tried with various software but with no luck.

Hopefully you have some good ideas! Thanks!

NusNus