looks like your site is using an older version of CKEditor that is not updated for compatibility with IE 10.
you can fix it by going to the CKEditor Site and downloading the most recent version.
on this page:
click the CKBuilder button. From the presets list, choose Full. In the plugins section, make sure that the Spell Check as you type plugin is selected.
in the skins section, select Kama.
In your DW Site, rename the webassist/ckeditor folder then copy the downloaded CK Editor file to webassist/ckeditor.
from the old webassist/ckeditor folder copy the ckeditor.php, ckeditor_php4.php and ckeditor_php5.php files to the new ckeditor folder.