SQL error -1 - SQL Network Interfaces

When performing a backup on a 64-bit edition of SQL Server, you may encounter the following error:

SQL Backup Pro is a 32-bit application and requires access to a 32-bit network client. This error arises if no 32-bit network client is available.

To make a 32-bit network client available:

1. Open SQL Server Configuration Manager.
2. Expand SQL Native Client Configuration (32bit) and select Client Protocols.
3. Make sure that one or more of the protocols inside the group is enabled.