I'd try to avoid this. One thing you could do is just go over there (or have him bring his computer if it's a laptop) and do the transaction right on his machine......
To answer your question though, it depends on how the software company does it's software distribution and installation. Often they will download a file (usually an .exe file) that when executed, runs a program that checks out the local system then initiates a download of the rest of the product from the company download site. Theoretically if the install file is downloaded and you can easily find it, then yes, you should be able to burn it to a thumb drive, go to his machine and install.....theoretically. The reason I'm hesitant is that companies today go to great lengths to protect against people subverting their copy protection and systems use policies. Sometimes that makes for install routines that are not as straightforward as they appear to the user.....
