SQL Server 2000 : Upgrade from Personal Edition to Enterprise Edition
I would like to post this as answer what is point in upgrading to SQL server 2000 which is outdated completely without any support. Even it is not good for testing purpose. Its like using typewriter in era or super computers.

Dont uninstall personal edition first. Install enterprise move databses by backup restore method. If you restore master msdb databases you would not need to move logins and jobs.

Please refer to below link

https://www.barracudaware.com/files/docs/9.00/help/restoring_microsoft_sql_server_2000_master_database.html