I see that you have a "Web Site" project. Of course you need to reference GleamTech.FileUltimate.dll. Then VS should copy GleamTech.FileUltimate.dll and it's dependent GleamTech DLLs to the bin folder.
If the DLLs are in GAC, then just specify full name of the assemblies in your Web.config so that they can be found (the versions below are for latest):
<configuration>
<system.web>
<compilation targetFramework="4.0" >
<assemblies>
<add assembly="GleamTech.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=a05198837413a6d8
" />
<add assembly="GleamTech.VideoUltimate, Version=2.0.0.0, Culture=neutral, PublicKeyToken=a05198837413a6d8
" />
<add assembly="GleamTech.ImageUltimate, Version=4.0.0.0, Culture=neutral, PublicKeyToken=a05198837413a6d8
" />
<add assembly="GleamTech.DocumentUltimate, Version=5.0.0.0, Culture=neutral, PublicKeyToken=a05198837413a6d8
" />
<add assembly="GleamTech.FileUltimate, Version=7.2.0.0, Culture=neutral, PublicKeyToken=a05198837413a6d8
" />
</assemblies>
</compilation>
</configuration>