Windows domain isn't working:

1. Check exact domain name by running command prompt

2. Use this command to find exact domain: echo %userdomain%

PowerOlap users have the same name as Windows Auth:

 PO users will trump Windows

1. Delete PO users except for Admin
2. Enable Windows Auth (Options >  Enable Windows Auth.)
3. Enter Domain name
4. Close PO Client, Save database, stop and start PO Server (or working stand alone: Save databases, close\open PowerOlap Client)
5. Go back into PO Client, check users for Windows Auth
6. Start changing over the rules for Meta and Fact data (inside Model > Cube), change the users over