You can set up SQL Server aliases on a Windows Server or PC using the Network Client Utility even if they don’t have the SQL Server Client tools installed.
The trick is to keep in mind that there are two different SQL Server Network Client Utility runtimes on a 64-bit machine.
If you are running a 32-bit Operating System, you will have only 32 bit drivers installed.
If you are using a 64 bit machine, the default utility will be for 64-bit data sources.
If you have a 64bit OS and are trying to access an alias in your 32bit application and receive the error check to see if you have an alias configured for the architecture of your application ( 32-bit / 64-bit ).
Use this utility to Review 64-Bit aliases and protocols
Use this utility to Review 32-bit aliases and protocols