Yeah, as of Lightroom CC.2015 and Lightroom 6, 32-bit Windows is no longer supported, and you can no longer buy an earlier version of Lightroom to get 32-bit support.
I'm surprised this hasn't happened more often, but evidently most Windows (and all reasonably recent Mac) owners have 64-bit systems these days.
Is getting a 64-bit Windows or iOS system possible for you to run Lightroom? If you are running a legitimately activated copy of 32-bit Windows7 or 32-bit Windows 8.1+, and your other hardware and software can run with a 64-bit operating system, you can get a free upgrade to Windows 10 which also is 64-bit only. Of course if you have WinXP or Vista running or an old 32-bit iOS version, Windows 10 is not possible. In that case is it time for a new computer and can you afford one? Part of the reason Adobe went to 64-bit only is that 32-bit systems generated a lot of complaints about glacially slow command execution even in LR5, and LR6 would have been worse even if it was possible.
If you bought the Lightroom serial number card directly from Adobe (as opposed to a third-party retailer like amazon or B&H), a refund from Adobe is possible in the first 30 days after purchase. You can contact Adobe here to ask for a refund:
If you don't meet the above qualification for a refund, try anyway on the grounds that you didn't understand you had to have a 64-bit system. They or your retailer may or may not be willing to help. Good luck.
There is no 32-bit version of Lightroom 6 or Lightroom CC. You will have to contact Adobe in order to get a refund. You can initiate a live chat session by clicking on the larger blue bar at the following link. That person will be an Adobe employee who can probably assist you in getting a refund:
Try Live Chat with Adobe.
Thank, Mel, appreciate the quick response. One of the local camera stores has a class in Lightroom that I was planning to take. Thought that getting a copy to start working with would give me a head start. I did finally hear that LR5 was the last 32 bit version, but based on your description sounds as if it will be pretty slow...unfortunately a computer upgrade won't happen just yet. I'm running Windows 7, and a free upgrade to 10 is available, so your suggestion sounds like a good next step unless a copy of LR5 turns up.