Hello!
What you can try to do is, first log in to
www.lfs.net. Use your username and WEBpassword (the same password that you used to log in to the lfsforum).
Mind you, I just looked at the account details and wrote the following (thinking of the logical steps - I haven't tried it out recently, so can't tell you if it will work as I expect it to!)
Then click on account details.
You would be able to update your e-mail address to something that is in use now.
Enter the new email address and hit "update account details" at the bottom on the page.
Now you can enter and re-enter a new GAMEpassword. Again, hit "update account details".
You are likely to get an e-mail confirmation about the updated GAMEpassword.
Now you should be able to unlock LFS S2 with the updated (new) GAMEpassword.
Before you format your PC, check if the above works.
Hope that helps.
Good luck! *fingers crossed*