My cell selection and render windows have disappeared off the screen. The main CS frame and the object selection window are fine. I've tried putting it on the highest possible resolution, unselecting/selecting them in the view menu, reinstalling morrowind and the cs; nothing seems to bring them back. Does anyone have any suggestions for getting them back on screen?

What OS are you on?
I know that sometimes on Win7 and Vista they do not appear at first, but simply minimizing/maximizing the CS fixes it. Or try grabbing the Object window and "shaking" it. The others will pop up. (this seems to refresh the CS or something)
That's what has worked for me when they don't load properly.

Are you using dual monitors? They could be sitting somewhere off screen.
Also, putting it on a lower resolution is likely to work better than higher. The CS is old