Fixed it...

I'm happy with the price, it's good value for 5 licences, but a bit annoyed that I bought a single licence when it was in beta not realising that I should have waited and bought the 5 licence option. That could have been communicated better to save me wasting money on a single licence.

Actually, I believe, if you just need the 5 licenses. You should be able to ask for refund on your 1 license purchase. You can use this link :

https://stardock.atlassian.net/servicedesk/customer/portal/4

Thanks
Basj,
Stardock Community Assistant

I also bought Start11 in beta.
How do I know if I have a single or 5 device license?

Edit:
I found the answer in this thread.

I purchased license for Startup 11 through an email when it was first offered. It is not installed on any of my computers. I installed it for the first time today and it won't activate because it says it is activated on another computer. How can I deactivate that device, whatever it may be, and get it to activate on this one? Thanks

Hello,
Sorry to hear you are having issues. Try this guide : https://forums.stardock.com/486311/accounts-and-activation-support-faq#deactivateproduct. Report back if you still need our assistance.

Thanks
Basj,
Stardock Community Assistant.

Thank you. That was helpful and successful!