Hi aquamanVSaqualad,
I'm Paul, a fellow customer like you & an Independent Advisor. Here are your options below for the Minecraft Java versions, however for the Windows version, it should automatically allocate whatever you have.
https://www.online-tech-tips.com/gaming/how-to-...
Try to open your Minecraft Windows game & check the actual memory allocation using "Task Manager", as shown below.
https://www.lifewire.com/how-to-check-ram-on-wi...
If it's allocating about 80% or more, then try to see if you're able to decrease its' usage by following the steps suggested below.
https://www.partitionwizard.com/partitionmagic/...
You can also set up virtual memory by following the steps below. Just ensure it's located on another hard drive (if any), as it might affect performance as well.
https://www.thewindowsclub.com/increase-page-fi...
I hope this helps. Let me know how you go. Thank you!
Sincerely,
Paul A.
Independent Advisor
(Note: There are non-Microsoft websites above. The pages appear to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.)