Used the same Microsoft account to add second drive to test Preview Builds.
Worked great except by using the same account on both drives, windows update wants to install the preview builds on both drives! How do I turn off windows update insider builds in the working win10 system (primary HDD) without turning it off in Win11 test system(secondary HDD) ?
UPDATE: found the fix. You can select 'stop receiving preview builds" in windows insider options on system(primary OS) and it wont disable it on the other system(preview OS).