安装oracle时建立的那个id和password，忘了。
------解决方案--------------------
用SYS用户去登陆
CONN /AS SYSDBA
然后修改密码
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C:\Documents and Settings\Administrator> sqlplus /nolog
SQL*Plus: Release 9.2.0.1.0 - Production on Thu May 10 12:57:48 2007
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
SQL> conn /as sysdba
Connected.
SQL> alter user sys identified by oracle;
User altered.
SQL>