This annoying bug crops up occasionally. I spent much time looking for answers and in the end the solution is pretty simple. First off, this option is only displayed in Internet Explorer. Secondly, if you are running IE and can’t see the option, check the add-ins enabled in IE (Tools-Manage Add-ons, show All Add-ins). If STSUpld.UploadCtl is not listed then run the Office 2010 installer and repair you installation. An alternative is to install SharePoint Designer and then de-install it, which should leave STSUpld.UploadCtl in your IE add-ins.