iTunes library sharing with Mcafee firewall

I've checked to make sure iTunes is allowed full network access through the firewall as well.

Also check to make sure BonJour is being allowed full access by your McAfee, Enjoi. (iTunes uses BonJour for home sharing.)

Perhaps try deleting the existing rules (for iTunes and BonJour) and creating new ones allowing full access to both applications. (On occasion I've been caught by rules "going off" after an upgrade, and replacing the rule helped with that.)

🙂 Steadily ruling out the possibilities.

... are multiple firewalls running on the PC? (For example, could the Windows Firewall have accidentally been switched on as well as the McAfee one?)