What is needed to handle "exFAT" used by 5d Mk IV on SDXC cards?

NOTE: I did some research and edited this to include comments about my computer.
The Canon 5d Mk IV formats all SDXC cards in “exFAT”, not in regular FAT. They say this can cause problems, and my current card reader or computer is definitely having trouble with the brand new SanDisk Extreme PRO 64 GB cards I got with my (brand new) 5d Mk IV.
I get a pop-up saying there is an I/O error some of the time, so sometimes it works, and and sometimes it doesn’t!!
Is this my computer or my card reader? I DO have an old computer; it’s still on VISTA. I don’t use it for anything except photo editing, and I have no intention of upgrading my PhotoShop.
I do not see on the specs for card readers what type of format system they will work with, so I don’t know if it’s that, or my old computer. My current card reader is about a year old.
Does anyone have use the SDXC cards (or 128 GB or larger CF cards, which it also formats this way) and have any issue like this? Is it
Sure would appreciate it if someone has experience with this issue.

I did more research into this. My computer, as old as it is, apparently can handle exFAT. Maybe it’s my card reader; I don’t know. Sometimes it reads it just fine, sometimes it won’t read it at all.