Logo is generated by the theme - in App_Themes folder. It can be removed from css file, the image could be replaced under /Images folder or you ca remove div element with id="wrapper" from your master page. Actually Company theme does not have company logo, probably you are referring to other theme.
If you are talking about Sitefinity logo -
you should "upgrade" your website. The logo appears for community editions - you need to apply Sitefinity patch for a standard version you use againt your website.
Let us know if there is anything else that we can do for you.
the Telerik team
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