先从控制面板删除oracle的相关应用及数据库，

删除系统变量

ORACLE_OEM_CLASSPATH=%JAVA_HOME%\lib\ext\access-bridge-64.jar;%JAVA_HOME%\lib\ext\jaccess.jar

.....

CLASSPATH=.;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar

PATH=D:\app\Administrator\product\11.2.0\dbhome_1\bin; C:\Program Files\PHP\v5.3;C:\Program Files (x86)\Internet Explorer;C:\Program Files\Common Files\VSL Utils;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Microsoft\Web Platform Installer\;C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\;C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;C:\Program Files\MySQL\MySQL Server 5.6\bin;C:\Program Files (x86)\PHP\v5.3\libeay32.dll;C:\Program Files (x86)\PHP\v5.3\ssleay32.dll;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\;C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\PrivateAssemblies\;C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\;%JAVA_HOME%\bin

打开注册表，查找oracle的相关服务项 即可顺路删除相关的注册表项。

查找：OracleDBConsoleLLS

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle.lls

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle.VSSWriter.ENDV

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle Services for MTS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle BI Administration Tool

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle BI nQUDMLExec

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle BI Scheduler

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle BI Server

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle BI Utility

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle Services for MTS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle.VSSWriter.ENDV

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle.VSSWriter.LLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\Oracle.VSSWriter.ORCL

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\OracleDBConsolells

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\OracleDBConsoleorcl

....

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Oracle Data Provider for .NET

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Oracle Data Provider for .NET

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Oracle11

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleDBConsoleLLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleJobSchedulerLLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleOraDb11g_home2ClrAgent

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleOraDb11g_home2TNSListener

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleServiceLLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\OracleVssWriterLLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle BI Administration Tool

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle BI nQUDMLExec

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle BI Scheduler

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle BI Server

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle BI Utility

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle Services for MTS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle.endv

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle.lls

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle.VSSWriter.ENDV

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle.VSSWriter.LLS

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\Oracle.VSSWriter.ORCL

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\OracleDBConsolells

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\OracleDBConsoleorcl

最后，删除相关目录及程序的快捷方式。

D:\app

C:\Users\Administrator\AppData\LocalLow\Sun\Java\jre1.6.0_24\

重起计算机后即可全新安装oracle的相关软件，包括oracle数据库。