compatibility

What version do you have? If you don't know how to find out, say. 

What do you mean "old"? Acrobat Reader is updated automatically, so if you download it, it starts with an older version and then updates itself soon. My version is 2021.001.20142, what is yours. Sure, it's 32 bit, there's no problem with that, though some people with 64 bit software to sell spread the lie that 32-bit is obsolete.