This is something that you should get used to as it is mostly standardized across a wide selection of software out there. Whenever you have the choice between two .exe-files, where one has "32" in it, you should always go for the one that doesn't. The difference is between 64-bit and 32-bit. The 32-bit option is there for people who have very, very old and limited operating systems, such as certain editions of Windows 7.Maybe this is common knowledge and I've just missed it, but Belle, what's the difference between the two .exe files? Is -32.exe a 32-bit version and the other 16-bit, or what? (And in any case, what's the difference in gameplay?)
It doesn't matter much for LLtP since this game doesn't use a lot of RAM, but it's a good habit to stick with 64-bit versions of software where you can.