I have been playing this game for some time but unfortunately I can't convert my creatures.

At the time I just thought it was an error and a patch/update would be made available but I see in the forum that others have been able to convert their creatures! Without this part I am unable to complete the campaign.

Does anyone have any ideas how to get this to work?

ta

What exactly do you mean by "converting" your creatures? I know you can convert the enemy's creatures (turn them over to your side) in the torture chamber, but I don't know what sort of conversion you are talking about in regards to your own creatures.

Edit:
And, not that it matters much, but are you talking about DK1 or DK2?

First make sure imprisonment is on. In DK2 look at the prison door, in DK1 it is the little prison icon on the first tab. Defeat creatures in battle and get your imps to drag them to the prison.

Heal the prisoner to make sure he won't die from torture. Now drop him in the torture chamber on a machine and wait. If he is about to die, heal him some more. Eventually they will join you.

Yes sorry badly phrased I meant the enemy's creatures!

It was DK2 - I didn't heal them first so will try that! Thanks for your help!! :)