2 domains, one website (.com & .co.uk)

Hi folks

Trying to set my site up with .com & .co.uk domains, the original site was hosted on .co.uk, but I have no transferred content to the ,com, all I want to do is have the .co.uk redirect to the .com.
I've set a cname record for the root domain and www. to the .com variant but get the below message.
Site not installed
The site ***** is not yet installed

You
Internet browser
Web host
OVH, cluster026
Website
Site access

I've also created a "multisite" as ovh calls it, to host an index page to html redirect but it doesn't create properly. Any ideas ?