If you are transferring data from one server to another server in transaction mode, you need to activate MSDTC (Microsoft distributed transaction cordinates).
In my scenario, I used MS SQL server A and MS SQL server B. SQL SERVER B is linked server of SERVER A.
I have same credentisals for both Windows 2003 and same credentisal for SQL server. To avoid network plot blocking I disabled firewalls from both machines.
Then from command prompt I started MSDTC
Net start MSDTC
If you changed the password of your sql server, you need to restart your MSDTC service.