Hello again and thank-you for your help and suggestions.
As kindly suggested, I deleted the Components folder and restarted the program, but found that the trial version no longer allows any export of the project (perhaps it only allowed a limited time initially?).
I found my original registration code but couldn't use it as it was an older version of the program. I repurchased the program, but am receiving the same error messages with any format except for .mpg. The error messages are:
"Error
ShellExecuteEx failed; code 1155.
No application is associated with the specified file for this operation.
Error
Failed to create your movie.
Could not initialize video output."
I don't understand why my newly paid version doesn't work for the other formats that I require to play on other media such as TV.
Any further advice would be greatly appreciated. Thank-you.