New Child Domain Query

I have My main Domain -> test.com and now I add another Dc and new child domain to that existing forest -> testchild.com

Now all my computers currently login as(at windows login screen) , username :test\user1

However now I want to get them to login to -> username: testchild\user1

Do I have to go to each Pc and change the domain from - > start -> computer -> properties -> change settings -> change -> then put in the new domain -> testchild.com

To get them to use the new domain when they login

I will have to setup each user profile from scratch which will be one helluva mission :/

Is there anyway to avoid setting up each user profile again?

Any idea's? tip's? advice ?

TIA

yes, changing domain's like that is a manual process last time i checked

The user profiles can be migrated via 3rd party software at the same time as changing domains.

@demon7 you perhaps know the name of that software ?

try profwiz or transwiz

You might need to use admt as well.