You can edit a previously created configuration.
From Setup, select TestNav Configurations.
Type a configuration name into the search field, and click Search.
Click the checkbox next to the configurations.
Click Select Tasks, select Create / Edit TestNav Configurations, and click Start.
Type/select details to the existing Precaching Computer associated with the organization.
To add a Precaching Computer, click Add and enter details.
Click Save.
When you complete configuring TestNav for proctor caching, you can create a session(s).