If you registered with Adobe then log into adobe.com, click Manage, and click though the Products & Purchases lists until you find LR 4 and see if the serial-number is listed.
![Windows Windows](https://blogsimages.adobe.com/lightroomjournal/files/2013/06/PSEEditor.png)
I got Lr 6 standalone for Macbook Pro from Amazon and have it all set up and running. I know I can have it also installed on my desktop (Win 10) with same license. I downloaded Lr 6 CC trial on my desktop before reading this: https://helpx.adobe.com/lightroom/kb/serialize-lightroom-cc-trial-to-activate-as-lightroom-6.html#If_you_have_an_active_Creative_Cloud_membership
Since I logged into CC with an ID I use for the standalone version, it activated a CC trial for my account. But the article says I can't convert Lr CC to Lr 6 while the account has CC membership. So I gotta wait until the trial is over before I can have Lr 6 running on my desktop?
![Lightroom 4 serial number mac Lightroom 4 serial number mac](http://www.capture-the-moment.co.uk/tp/tfu29/upload/LR_order_1.jpg)
In short: I purchased Lr 6 standalone for Mac, but want is also setup in Win. But my account has a trial CC membership associated with it. How can I download and use Lr 6 on PC?