Problems in creating a database using DBCA under Windows XP and how to resolve it ___ database

It's okay to be at home today. Oracle database installed.

After the database is installed, use the Oracle DBCA tool to create a database against the "apply Oracle" book. In the final step, a ora-27102 out of memory error is ejected. On the internet to find a, said is the SGA set too large reasons. Since my operating system is Windows XP, the memory is 4G,SGA set to the size of 2.9G, trying to adjust the SGA to 1.9G, mainly to the buffer cache large size from 1.8G to 1G, and then create the database. No more of these errors occurred during the creation process.