Migrate Oracle Windows from 32 bit to 64 bit

Create the Oracle service on the 64bit system, using the ORADIM command.
oradim –new –sid orcl –startmode auto –pfile c:\oracle\product\11.1.0\db_1\init.ora

Run Sqlplus
Issue the command: startup upgrade.

Run the script:
cd
c:\oracle\product\11.1.0\db_1\rdbms\admin\
--This script invalidates all the objects and change the word size
@utlip.sql
--This script recompiles the invalid objects
@utlrp.sql