Quicken told me I can't have two databases on one program of Deluxe on the same computer?
I need to have two data bases on one computer, one is my company and the other my personal.
Can I do this with one Deluxe version of Quicken?
Of course you can. You can have as many Quicken data files as you want. It's quite common for users to have a personal data file and another for their business, or for parents, or for a nonprofit group, etc.
What you can't do is have two different data files open at the same time. Perhaps that's what Support thought you were asking for? You can pretty easily move back and forth between two data files, using File > Open Recent, but Quicken will close one file to open the other.
As pointed out, you can have multiple data files with one copy of Quicken. You simply cannot open them at the same time.
If you really have such a need, there are 2 workarounds to be able to open 2 data files at the same time: