The tnsnames file is not on the c:drive anywhere.
tnsnames.ora is a text file, and you can create it with any editor. It can be in ORACLE_HOME\network\admin, or wherever you want, and you can specify its location by setting TNS_ADMIN environment variable. A typical TNS entry can be
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(SERVICE_NAME = ORCL)
But you may not need it, see Configuring Naming Methods
It was the .exe file I was using to install. We had a file here locally that I thought would work but it did not seem to install everything I needed. I grabbed another one off the internet and installed it. I could tell right away that it was installing more than the other one. After I did the install, I copied the tnsnames file that a co-worker had onto my pc and I can now run BOXI reports.