OS = Windows 7 Pro. x64 SP1 LO 64-bit = v5.2.4.2 (en-GB) and also the associated Help-pack for en-GB. (This combination was installed first.) LO 32-bit = v5.2.4.2 (en-GB) and also the associated Help-pack for en-GB. (This combination was installed second.) I did a dual install of LO 64-bit and LO 32-bit to my Windows 7 system. I was just wanting to tinker around with the two versions and see which I preferred. Eventually I decided to go with LO 32-bit. I went to Windows "Programs and Features" and looked to uninstall the 64-version. When I look there all that was shown was one uninstall option for LO (when I actually expected two uninstall options to be available, one for 32-bit and one for 64-bit). So, in effect, doing two installs of LO (one 32-bit and one 64-bit) only results in one uninstall option. I thought this a bug with the installers (or it if it isn't it should be flagged as a possible bug). Really the installers for LO 32-bit and 64-bit should check to see if there is already a different version (32-bit or 64-bit) already installed and, if so, then a separate entry for the new version being installed should made in "Programs and Features". (I hope I have explained all this clearly.) I would also note that the same situation exists for the Help-pack installers (32-bit and 64-bit) - there is only one uninstall option. So I would say that those installers are also bugged. Hope this helps.
I would like to add to the above that some users might want to experiment with having LO 32-bit and 64-bit installed to the same Windows system. And on that basis it might be a good idea to have them install as completely discrete (separate) installs i.e. not sharing any of the same user data. (As things stand I have a suspicion that if both are installed to the same system then they might be sharing the same user data - which might not be what the user wants.
It's no possible to have installed both version in the usual way. So only the last installed it's the installation. There is chance to install in parallel so many version like you want. https://wiki.documentfoundation.org/Installing_in_parallel/Windows I have about twenty five.