Photoshop problem

[Stormtropper]

All right, I start up Photoshop (CS), and then goes over to "File/Open"...find my picture...and click "Open"...

...and nothing happens.

Same thing wiht "File/New"...and it even lets me pick the document size and everything...but as soon as I press "Ok", it just goes right back to the same blank screen that you get when you first start Photoshop...

...also, once in a while when a image does manage to open, I can't edit it in any way and I can't save it, unless as a jepg.

Thanks in advance,
Jeff