I'm helping out some friends with a tiny hospitality business where one desktop computer has some files used by the business in one account "hotel" but it's mostly used by guests for browsing the web in another account "guest".

It's low security, we're not worried about hacking or anything. But we don't want people accidentally moving our files or anything either.

But the system always boots into the "hotel" account without asking for a password, even though the account has a password.

We want it to boot into the "guest" account.

I know a bit about computers generally and Linux but not much about Ubuntu and the ever-changing graphical environment the Linuxes are going through these days. We've looked through the obvious settings/preferences/options and I've done some Googling. I know this should be obvious easy stuff but I can't find it.

(We're running 10.04 LTS on a generic aging Intel box.)