Renumbering sequence of filenames?

For reasons best known to itself, my Canon Powershot decided to reset
its filename sequence back to zero, so although my library of photos had
incremented up to the filename IMG_1432.JPG, I suddenly find myself with
a new set of photos starting back at IMG_0001.JPG again. What a PITA.

Now, I've solved the original problem and stopped it restting, but I
want to renumber the new files starting from IMG_1433.JPG. Life's too
short to do it manually! Any ideas how to do it? (using Windows XP Home).

I'm sure there must be a way using old MS-DOS commands in the XP command
window - but how?

Thanks
David