did you try a restore from when the program was working ?
next step
my suggestion which may or maynot help
is too get something like "Ashampoo uninstaller"
this program is actually an install monitor
run the install monitor
install corel videox6 again, completely, even try to open and use it
then after the 'installer' has recorded/saved all this info
reboot the PC, use the 'installer' to uninstall the program
it will delete all registry entries , all files, everything
reboot the PC again
and try a clean install
some critical file or entry has been changed/corrupted
and this might remove