Hello Jarmeister,
Here is what you will need to do:
- for On-Demand scan, create a profile in which you add all drives, then exculde (uncheck) the drive you want it not to scan.
This guide will help you with creating the profile:
https://www.bullguard.com/support/product-guides/bullguard-internet-security-guides-14/antivirus/scan-profiles-create-antivirus-profile-%28guide%29.aspx
- for the On-Access module, "Skip files/folders" and add the HDD you do not wish to have scanned, or folder from the drive that you do not want to be scanned.
This guide will help you with the settings of the On-Access module:
https://www.bullguard.com/support/product-guides/bullguard-internet-security-guides-14/antivirus/antivirus-settings.aspx
There is one more setting, the "Don't scan removable media" option from the Tuning option under the Antivirus settings. Checking this box disables the On-Access monitor to actively scan any removable devices that you plug-in, from the moment you start using them.
Please let me know if this information solves the issue, or if you have any more difficulties.