Quentin, did you reboot your machine between uninstall and reinstall?

If you can get SD to open after reinstall, then don't open that project again. Start from scratch. If you need to see what you have done so far, look at the exported pages. And if you don't have any exported pages, or if they don't open either, I can send you the exported project that I've made here.

Thanks so much....ok, doing the file cleaner, will follow the instructions and let you know soonest.

Hi...just to update. Did the thorough uninstall, rebooted and opened a file from backup. The image shows the result, the right section disappeared again.
I'll follow the suggestions on here, do the uninstall and design a new site, see if it happens again. Might be a late night for me, tonight. They are starting to ask me for progress, (the client), believe it or not they care more about what the site looks like than what it actually does.

image

Well Now here is something strange

I started a new project today

Would you believe it,, THE SELF SAME THING IS HAPPENING TO THIS PROJECT !!!!!

so sorry to hear that. You might find that it, (the problem), will disappear/reappear intermittently. I must say that the response from both Coffee Cup and the Forum has been absolutely wonderful so I haven't any doubt the problem shall be discovered. Have you, too, uninstalled?

Nope
Now I am experiencing difficulty changing a background image it doesn't change the image unless I save the project, then change the image and it changes ok, go to the next one have to do the same all over again,

I found the problem with the right thingy disappearing for some unknown reason whenever preview on was selected, so was preview which of course doesn't show that right hand pane, normally it has a red underline to show its active but this time it doesnt,.

I am suspicious that it may be something to do with the latest windows update which I installed earlier this morning, I am going to remove the update and see what happens

Yesterday, after having had Quentin's file open for a bit and played with it, I also had the tool panes disappear. I also tried Preview and 'Preview on', and I noticed too, that the red underlining under Preview was gone, without thinking further about it. Afterwards, I tried that Revo uninstall/cleaning that Wayan recommended, actually for no other reason than just to find out how it works.
Now, by reading Wayan's post, I'm glad I did the uninstall and reinstall of SD. The red line is back under Preview for starters.
I see now in the systray that there is some windows update, sitting there waiting for a machine reboot...

Later: I'm up again after the machine reboot, and the red underlining is still there.