Can you clarify if it's an upgrade or a rollback? Either way neither should take multiple hours. But we'll try to help you get it going again!
Next to Edib's reply, it might be good to first have a look at the "localhost" tab page of this Upgrade popup (you're currently viewing the "general" tab page). That way you can see where it is stuck.
Also the upgrade log itself might show some more information, this is located in C:/Skyline DataMiner/Upgrades/Packages/<your upgrade package>/progress.log