I have several thousand photos to sort, the problem being that many need to be rotated.

This isn't a problem as both viewer and explorer can rotate images (I haven't got time to open each image up in an application, rotate and then save). However, it seems to be totally random whether the image is saved in its new orientation or whether it reverts back to its original position.

I've just worked through two folders in seemingly the same way. The first is fine, the second has reverted back to how it was.

Any thoughts greatly appreciated.

Red

When rotating multipul images I use photoshop as you can set it to do a Bulk edit, where you do a macro with one image then it will do the same with all the rest.

The second folder was probably set to read only (possibly due to being copied off a CD?) whereas the first was probably copied directly from the camera or card and therefore had write permissions enabled.

Just a guess, if you right click on the folder and select properties it will confirm what permissions are set.

Hope that helps,

EDIT: It's worth remembering that all files on a CD have read-only permissions, and keep those permissions when copied to a hard drive.