There could be a time when you just want to change the live ID account you have been using on your phone for some reason any how, this live id is that id which you have configured for the first time when you started using your windows phone 7 but now you would like to configure some other id on your windows phone 7.
Follow the procedure below to know how to change the live id on windows phone 7
To verify the Windows Live ID used to access features like Marketplace, Xbox LIVE, and Zune Pass from your Windows Phone 7:
1. On Start, flick left to the App list, tap Settings , and then tap email & accounts.
2. In the list of accounts look for the first account named “Windows Live”.
Tip: If you renamed your first Windows Live account to something other than the default name of “Windows Live”, look for the first account with the Windows logo next to it.
In order to change the Windows Live ID used to access features like Marketplace, Xbox LIVE, and Zune Pass from your Windows Phone 7, you’ll need to reset your phone to its original factory settings. However, other email accounts, including additional Windows Live accounts, can be removed without resetting your phone.
WARNING: Resetting your phone to the original factory settings will erase all of your personal content, including apps that you purchased and downloaded, photos, videos, and music, and will restore the phone to its original factory settings. You may not be able to transfer purchased content to a different Windows Live ID.
If you are really sure you want to change the Windows Live ID for your phone, follow the procedure given below
1. On Start, flick left to the App list, tap Settings, and then tap about.
2. Tap reset your phone and follow the instructions to complete the reset of your phone