OK, so you are using X86 instructons, if you had told us that in the first place we would have been able to answer the question.
I'm not sure if it works under later versions of Windows but certainly up to XP there is a command line program called 'debug'. Read the help file for it or type '?' at the prompt for a list of instructions. Then use the 'L' (Load) or 'E' (Enter) command to load the hex data at an address you choose and the 'U' (Unassemble) command to convert it into assembler instructions.
Another excellent program although no longer supported is "Sourcer" from "V Communications", if you can find a copy. If your hex is actually a program for a PC, this one can also add labels and name the calls to the BIOS routines which makes the listing far easier to read.
Eric Isaacson's A86 and D86 package should be able to do it.
And of course the one you named, IDA pro. I think there is a 'demo' version available which can probably do the job for you for free.
Note that there are several formats of hex file, you may have to convert the data to make it suitable for use or even convert it to raw binary.
Brian.