There have been several issues with this part of the program. On the Corel site, a similar problem was solved when the user changed from 5.1 AUDIO to 2. stereo. To test yours, turn off the audio capture to see if the error message goes away. There are other posts that you can search for using any search engines.
Did you try to do a repair on NXT6 with your antivirus OFF? Remember that repair is not counted as an install. The number of Installs are limited to prevent copying and selling copies of the program.
By the way, if you run a Windows dxdiag.exe on your computer, it will tell use more about your computer than what you post. There is NO personal information except what you named your computer. Just post it as an attachment See below.