My son just got his new xbox360 and his friend helped him set it up. He changed his gamertag from the one originally set up by xbox, to one that he wanted.
But, he never deleted the original gamertag. So, when he went to add his microsoft points, in haste, he added them to the original gamertag(which isn't attached to xbox live) not the gamertag he actually uses.
I tried to switch his gamertag to a different Windows Live ID, but it won't let us because it states that "the Windows Live ID your switching to is already linked to another xbox live account. You must use another windows live ID."
All I want to do is switch his microsoft points from one gamertag(not connected to xbox live) to another gamertag(which is connected to xbox live). Can I do this or did he just lose his microsoft points?
Nothing can be transferred between accounts.
You cannot transfer Microsoft Points from one account to another. But you can try phone Xbox Support and see if there is anything they can do for you. Good luck.
Points cannot be transferred between accounts, except in the case of a primary on a family plan transferring points to a secondary on the family plan. Phone support will tell you the same thing, so if you wish you call them you certainly can, but you will get the same answer from them.
There is a semi-solution though. When you purchase content you are given two licenses, an account license and a console license. If your son were to buy something with those points and first download it on the console he plays from, his newer account will be able to access that content as well. So the points aren't entirely lost, but if you ever got a new console you would absolutely need to make sure you do a license transfer for the other gamertag to have it continue functioning as intended.
Call support and let them know you accidently redeemed the code on the wrong account. If none of the points have been spent, they may be able to help you. Otherwise, purchasing the content on the one you redeemed the code on will work for the most part. A few items are none transferrable between accounts such as avatar items.