Thanks for posting!
Do any other users connect beside him? If not, then a server won't necessary. You can just move the .fm5 files to his workstation and open them in FileMaker Pro directly.
If he does have other users connecting, you'll need to install FileMaker Server on a different machine and host the files from there. If this is the case, you may want to check out the FileMaker Server 5.5 Administrators Guide available here:
FileMaker Pro 5.5 can also host the files provided you have a small number of users accessing the file. You open the files with FileMaker on one computer and the others would use Open Remote... to access the hosted files. 5.5 does support 3 different network protocols unlike today's version so if he didn't set up for TCP/IP, you may have to check on network protocol settings as well.
You might point out to your client that the days he can continue to use a version as old as this are probably numbered...
Thanks much guys. I have the latest files, and I'll just drop that folder on to his workstation and let him run it from there. It's only one user, so a server seems overkill, and this "server" which isn't a server at all, will enjoy a much overdue retirement.