Resolved [Unable to move or delete some Corel Wordperfect files]

I'm using Corel Wordperfect 8 on a windows 7 Lenovo Thinkpad. I don't know why but on some of the files, generated using Corel Wordperfect, gives me the following error when I try to delete or move them, " The action can't be completed because the file is opened in Corel WordPerfect version executable." Why is this happening? Help!

 

And if that doesn't work, I'd next try deleting them in Safe mode.

(To get into Safe mode, turn your computer off, wait a few seconds, restart it, press and hold [F8] during the initial startup and then when the menu comes up, use the arrow keys to select Safe mode. If you are prompted to select an operating system, use the arrow keys to select the appropriate operating system for your computer, and then press ENTER. Log on as an administrator or with an account that has administrator credentials).