Unable to reset an OLD Apple I.D. So I can Not Hear My Purchased Songs

Reseting my password in my actual ITunes account (NewAccount@ATT.net) does not help me when some of my songs have been purchased on an older Account (Old Account@comcast.net).
This old ITunes account (oldname@comcast.net) has been disabled by ITunes, for security reasons (too many times trying to re-set it (@Comcast.net) trying to reset so I can hear my old songs / purchases, but since I don't have a Comcast.net account anymore, the Password re-set link is being sent to Comcast.net, and I don't have access to this account anymore).
So all these songs that have an old licence still appear in my actual ITunes song list, but ITunes does not allow me to hear them because the purchase licence is not up to date, even tough I have authorized my new PC and it's up to date on all the new updates.
Any suggestions?

The suggested site: http://iforgot.apple.com/ takes me to re-set my actual password / Account(ITunes Account= Internet Provider (@ATT.NET.
I need to re-set my old password in my old ITunes account (when I had COMCAST.NET)
This old ITunes account was open when I was with Comcast.net, where some of my songs have been purchased /Licenced then, (Subscription with Comcast.net,now I have ATT.NET).
I need to know how to renew the old ITunes licence (COMCAST.Net, where I bought my first songs in ITunes.
My new PC has been authorized by ITunes,