To my knowledge, you should be able to reinstall with no issues.
However, before you reinstall you may wish to try performing a reset. You do this by deleting a small file where Captivate is installed. I'll be happy to share my location, but if you are on Vista, I'm unsure exactly where this location will be. I'm using XP Pro.
Open Windows Explorer and navigate to:
?:\Documents and Settings\??????\Application Data\Adobe\Adobe Captivate
? is your drive letter (C or D)
??????? is your logged in user name
Once there you should find a file beginning with captivate and ending in .dat. Exactly how it reads depends on your Captivate version.
Note that you may not see this folder until you first adjust Windows Explorer. You may need to first click Tools > Folder Options... > View tab. Then ensure you have the option Show hidden files and folders selected. And the option Hide extensions for known file types DE-selected.
Delete the dat file (or rename it if you are feeling hinky about deleting)
Restart Captivate and see if stability is improved.
Thanks for your very helpful advice. I found the file it was exactly where you said. I deleted it after saving a copy and tried again, but to no avail. I have become quite disillusioned with Captivate 4 it held out so much, but it is turning out to be very buggy. To date we've had, and reported: White screens when moving the play-head in the timeline followed by Captivate crashing; files bloating and never shrinking including a 55Mb whopper which was just a plain old yes/no quiz question sitting there on its own; and now import failure when trying to move a single slide from one project to another. And if you pile on the issues reported in the forum I'm not really sure that Cap 4 in its present state was fit for release.
We've tried XP and Vista, we've run at admin level, we've disabled user access control (Vista), we've turned off all services not directly connected with Captivate, we've turned off all security software just to try to encourage it to work.
So our last desperate attempt is to try a reinstall. If that fails then I don't know what. I wouldn't mind if it was a $50 piece of shareware but this really sucks.
Thanks for your help,