A few more details will help(and hopefully, on of the moderators will take a look).
#1-was the package purchased new or second-hand?
#2-If second-hand, was a Transfer of Ownership form submitted?
#3-Have you seen any deals for an "upgrade" vs simply buying the current version(just wondering if the old software is so old as to not be a candidate).
#4-is the iLok registered to your account and are you able to log in to the iLok manager?
Then, what's your plan for the future? New Mac or PC? Pretty sure the Eleven Rack will still work. PT10 software might work on a new PC on Windows 10, but new Macs will have Catalina, which will require the very latest version of PT.
I can relate on forgetting login info. I'm so old that I now write stuff down on Post-It sheets and stick them under my desk
