The current installing user may have access to both as a Domain Admin, however, the specific account will need to be applied to both directories.
So for example, if you are logged in as:
DomainName\BobUser as a Domain Admin - Registered under Domain Admin Account
But the install was done as:
DomainName\DaveUser
Then you can either log in with .\DaveUser and retry the install or set the specific \BobUser with full permissions to both the NetVault Install and NetVault Database directories and rerun the install.