i thought i would add to this as i had the same problem and tried the above and it didnt work for me. so for anyone using the search function,
i searched the microsoft knowledge pages and found a similar fault and solution that did the job, so for anyone with a viavoice error message when opening the control panel, try this....
open search for files and folders and search for `setnote.cpl`
if this appears as setnote.cpl then simply change the last three letters to bak to give `setnote.bak`
if your search only shows `setnote` then you need to open my computer/tools/folder options/view and uncheck the box that says hide extensions for known files. you should now see setnote.cpl and can change the name.