Need help with Outlook 2007 settings

I have installed Outlook 2007 on a friend's laptop (running Windows 8).
I set up his main email account (gmail). All fine.
I then set up another account (btinternet). Again all fine.

The problem is that, in the folder pane, the btinternet inbox & folders do not appear. And, when emails come in, whether they're aimed at the gmail or the btinternet account, they all appear in one mixed up inbox.
How do I separate the two account inboxes, emails in & folders?

I have set up Outlook of various flavours successfully several times, including on my own Win8 machine.

Any suggestions? Thanks.

If you want to keep them separate I would suggest setting up different Outlook profiles for each, then choose which profile to use each time you start Outlook.