Hello,
Sorry to hear you are having trouble.
Please tell me in detail about it because steam support has failed to give information about it.
If you run into a limit, it indeed should prompt saying so...
And how to deactivate it on my current pc or check how many activations left there.
You could PM the (long) number (SteamID) and I can reset it. We are working on a self reset that current SD store products enjoy but it has not yet been released.
----------------
Sean Drohan
Stardock Customer Service Manager