i have forgoten my email id used for my xbox account my gamertag is countdrakk2 and i am...

To Techmod, im not trying to combine two gamertags really, just eliminate my currently unused gamertag that has a xbox live / windows live id / email address. The offline gamertag is my primary and i wish to make it my gamertag / widows id / email address.
The offline account with my achivments is the account i wish to have xbox live with. If i sign up with xbox live gold membership on my offline account, will this delete my other live account? How do i do this.

Thnks for the reply, let me explain you in this way (Again)

My email account (*** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. ***) has his own gamertag (zzzxy), now i didn’t knew, this gamertag was created many years ago, however I never used.

Now I have a gamertag on my xbox360, without an email account (live ID if u wanna call it).

When I’m trying to remove/transfer/swap my gamertag to another email account, the system doesn’t let me. That’s the problem. I know I have to remove my old gamertag so I can register my new gamertag with my old email account.

If only that was the case. I did not lose my email that was attached to the Windows Live ID/Account, I've lost/deleted the Windows Live ID/Account as a whole. This is resulting in error status code: 8015D080 because the Gamertag is no longer linked to an
active Windows Live ID/Account. My question is as to whether I can attach a new email/Windows Live ID to the Gamertag.

Thank you for such a prompt response. I neglected to say that I did try to delete/change my Xbox live email to add my Hotmail email. This did not work as I have used it on my PC to set up this account and therefore I get an error on the Xbox saying
that the ID I am trying to use is associated with another Xbox ID. Therein lies the issue. How do I delete this account so I can use the email attached to it on my Xbox account? Also I can't delete the Xbox live account as I went "gold" with that account.
Can "Gold" status be transferred to the account? If it can then that may be a solution to this issue.

the bit that i am having an issue with is as follows

Change the WLID associated with my gamertag.

If for any reason you want to change the WLID you have associated with your account, all you need to do is follow these simple steps.

1. On the console, go to My Xbox, and select your avatar.
2. In Account Management, select “Manage Account”.
3. In Your Information, select “Windows Live ID”.
4. Select “Change Windows Live ID”.
   1. If you have another Windows Live ID, select “Yes”.
      
   2. If you do not have another Windows Live ID, on a computer, go to Welcome to Windows Live ID, and click “Sign up”.
      
5. Enter the password for the Windows Live ID that is currently associated with your gamertag, and then select “Sign in”.
   
6. Enter the email address and the password for the new Windows Live ID that you want to associate with your gamertag, and then select “Sign in”.
   
7. Select “Yes, change” to change the Windows Live ID associated with your Xbox LIVE account.
   
8. Select “Update Contact Information” to update your contact information, or select “Done” to finish.
   

As i dont have another Windows Live ID i have to create 1 using my correct email address, every time i try it says that there is a problem and to try later. I cannot transfer my Gamertag to the correct email address until i have the email address set
up as a Live Account.
Hope thats a bit clearer for you.