"TNS-03505: Failed to resolve name" error when trying to connect to database. (4260578)

I am having an issue connecting to a database with the error "ORA-12154 TNS:could not resolve the connect identifier". I have copied over the entry in tnsnames.ora entry from the $ORACLE_HOME/network/admin/tnsname.ora to the tnsnames file that Spotlight or Toad for Oracle uses, but with no success.

I am able to connect to another database on the same server without any issue, but if I try to tnsping this database from Command Prompt or Line, I encounter the following message:

G:\>tnsping ASPROD
TNS Ping Utility for 32-bit Windows: Version 10.1.0.2.0 - Production on 07-MAR-2
Copyright (c) 1997, 2003, Oracle. All rights reserved.
Used parameter files:
TNS-03505: Failed to resolve name