Are fonts embedded?

I need more help on this. We've been having our end-users test out our training with standard fonts on their systems (due to organization restrictions, they have to use Internet Explorer and don't have control over the settings), and not a single font is displaying properly for them... The server is configured properly for all the fonts used, and we're at a loss for workarounds.

We're publishing in HTML5 only (not allowed to use Flash) and using the Classic player. The training is used in a WordPress-based platform/website, and all of the site fonts display properly except those inside the training. The fonts on the site are standard sans serif fonts, but every sans serif font used in the font testing version of the training (Segoe UI, Arial, Calibri, Candara, Franklin Gothic, Verdana) ends up with serifs and spacing issues, and some of them are even missing characters. 

Please tell me there's a way to make this work? It appears that the only thing they're having trouble viewing are the fonts in the Storyline training itself. Everything else on the server is displaying perfectly. I'm at a loss, and this is our biggest customer so I have to come up with a fix. Thank you.