How the blue caddy is removed depends on what size the 790 is. [IMAGE] There is no one size fits all for all models all sizes. MT (Mini Tower)DT (Desktop)MFF (Micro Form Factor)SFF (Small Form Factor)USFF (Ultra Small Form Factor)AIO (All-in-One)   [URL] [IMAGE]  
  The presently installed internal hard drive has a nifty "blue cradle" that slips into the enclosure housing. Doe this nifty cradle come with a new hard drive  and if not how is it removed for reuse?
How to install a new internal hard drive on an OptiPlex 790