方法一：控制面板卸载
最简单的卸载方法是通过控制面板的添加/删除程序来卸载。
方法二：msiexec命令卸载
还可以通过命令行的方式来卸载
1.获得你安装的版本，每个版本都有一个产品号码 product code
2.寻找msiexec文件，C:/WINDOWS/system32目录下
3.输入msiexec.exe /x {5DC8D05F-2FEA-4D8B-B300-A8F2F758C53F} /qb，这就表示静音模式卸载ArcGIS Desktop 9.0
下面是官方公布的方法：
To uninstall a product silently use the following Windows Installer command line:
msiexec.exe /x <{product code}> /qb
For example, to uninstall ArcGIS Desktop 9.0 silently, use the following command line:
msiexec.exe /x {5DC8D05F-2FEA-4D8B-B300-A8F2F758C53F} /qb
The following are the product codes for ArcGIS products:
ArcGIS 8.2
ArcGIS Desktop {A149DEA2-1D5B-11D5-9F76-00C04F6BC7A1}
ArcGIS ArcObjects Developer Kit {52069752-B5E9-11D5-8110-00C04FA070E5}
ArcGIS Tutorial Data {440A069B-9016-11D4-80CB-00C04FA070E5}
ArcInfo Workstation {0AD11430-1D5C-11D5-9F76-00C04F6BC7A1}
Sample Maps and Digital Books {0B1DE126-4340-11D4-A0E2-00C04F68E699}
ArcReader Standalone {F8163054-45C3-4606-A11E-4DDED63C1DCB}
ArcGIS 8.3
ArcGIS Desktop {A149DEA2-1D5B-11D5-9F76-00C04F6BC7A1}
ArcObjects Developer Kit {E4A065AE-49E5-4F00-8A6E-41494C0D71E1}
ArcGIS Tutorial Data {E3B8F189-2C19-473F-811B-1748187F98E2}
ArcInfo Workstation {0AD11430-1D5C-11D5-9F76-00C04F6BC7A1}
Sample Maps {906719EE-0A9B-4AFA-8B32-44E0265F8B37}
ArcReader Standalone {8B162101-FC35-40E8-992C-72D60E93B96E}
ArcGIS 9.0
ArcGIS Desktop {5DC8D05F-2FEA-4D8B-B300-A8F2F758C53F}
ArcGIS Desktop Developer Kit {E4A065AE-49E5-4F00-8A6E-41494C0D71E1}
ArcGIS Tutorial Data {6AC7F416-78D5-4D98-B104-F8A39B2CF3A7}
ArcIMS {F04DC097-19C0-42FE-AB0B-D4A1CFFD184D}
ArcReader stand-alone application {2A4478CE-A91F-4614-BFF0-C0E89DD7BDE1}
ArcGIS Server {01F5DD11-0EF6-4990-B4C4-516A2F0B04D8}
ArcGIS Server DotNet ADF {1A4D1A36-F333-40F7-A7D9-1FEE5BDD0991}
ArcGIS Server Java ADF {9B999457-8FDC-4E38-9121-9F2EE53DB937}
Engine Runtime {19A3A1A7-2A87-47CB-BE11-E46A5BBDC1B1}
Engine Developer Kit {7BD74F39-151F-422C-A3C0-47F3F57553C9}
ArcInfo Workstation {02149814-393E-4E19-8CA4-FE096093695B}
ArcGIS 9.1
ArcGIS Desktop {40F8FD5F-4701-48D6-A8FC-1F188007DF38}
ArcGIS Desktop Developer Kit {3E166714-D5E1-4215-8D68-58452EAA46F1}
ArcGIS Tutorial Data {E0CA85B5-113A-4E76-A018-6D7ECE65767D}
ArcInfo Workstation {0C35348E-DA25-44E2-AF7A-78BF9C12C5EE}
ArcGIS Engine Runtime {7A2BB4EB-126F-4958-A47B-1F5340600DA1}
ArcGIS Engine Developer Kit {8ED91E21-5237-4762-A42D-175E71B8165E}
ArcReader stand-alone application {C675A5D9-E38F-42F0-B862-C46C3CC93D5F}
ArcGIS Server {529CC8E9-5F7C-46AB-87CC-480A44F1A718}
ArcGIS Server Dot Net ADF {885466F5-21D6-4927-8882-E9405BBFFB98}
ArcGIS Server Java ADF {957C3C56-6283-4E45-A873-CE7DA4BC5CF4}
ArcIMS {982EAE44-0024-4B21-B90A-13DDF7F541A7}
ArcGIS 9.2
ArcGIS Desktop {1F34839E-4826-4B64-B1B3-42E5AE8DEC5A}
ArcGIS Tutorial Data {1032F58F-D319-42C1-A25F-2D3C9A26705B}
ArcGIS Desktop SDK for the Microsoft .NET Framework {0CCCA447-8A01-41E2-92D0-5B8ED1E7B665}
ArcGIS Desktop SDK for VB6 {DEE23DF7-BB97-46DE-B384-0DCB0F5DF0A9}
ArcGIS Desktop VBA Developer Resources {1FD0DD4B-A072-4FE7-BDCD-84E3B1302678}
ArcGIS Desktop SDK for Visual C++ {FE5655A6-E2DF-4BEA-97B8-4F9A11F44747}
ArcGIS Engine Runtime {9B139B36-F1FF-4DB8-89F9-4DA3D5C12BE8}
ArcGIS Engine SDK for C++ {4E2A301F-8A7B-447F-AF24-1ED1C9E69A81}
ArcGIS Engine SDK for the Java Platform {17A643B2-A659-4859-AEEB-D1CD6A62FC8D}
ArcGIS Engine SDK for the Microsoft .NET Framework {7132A6AB-FB83-4E81-98E0-88F748AA9DD4}
ArcGIS Engine SDK for Visual Basic 6 {84A7AF81-6B9F-44D0-8316-682C3CB09748}
ArcGIS Engine SDK for Visual C++ {571AA05F-FDAE-40A0-9979-A91C3E2BD5F9}
ArcGIS Help System for the Java Platform {DB78CD8E-77D9-450F-9150-B68DDCFE75AE}
ArcInfo Workstation {494D3701-9D5E-44AC-BF3B-1BC682EE797C}
ArcGIS Server for the Microsoft .NET Framework {B4E1F242-76E1-4C8C-BF15-59DED0EE6D8C}
ArcGIS Server for the Java Platform {00B1C980-318A-4505-A578-5FA9825A2AFB}
ArcGIS ArcIMS {752AE27D-0AE5-4728-B615-308926C04A91}
ArcIMS Web ADF for the Microsoft .NET Framework {9620E027-4D61-4DE3-BB68-5632565BA546}
ArcIMS Web ADF for the Java Platform {0DBB552C-BEB3-4385-BA79-DCB2AD6CD29D}
ArcGIS ArcReader {191DCDE8-C24A-495D-AEA7-F7F07F4AA70F}
方法三：光盘卸载
如果已经安装过ArcGIS，那么仅执行卸载可能并不干净，这时可以通过ArcGIS desktop 光盘的setup带/cleanup进行环境变量及注册表的清理工作。这样再次进行ArcGIS的安装就相当于在一个以前没有安装过ArcGIS的环境下 进行ArcGIS安装。
转帖如下，
(http://www.esricanada.com/english/suppo ... /ilm15.asp)
=========================================
How do I do a clean uninstall and reinstall of ArcGIS?
如何完全卸载并重装ArcGIS
Software: ArcGIS - ArcView, ArcEditor, ArcInfo
软件: ArcGIS(包括ArcView, ArcEditor, ArcInfo版本)
Version: 8.1.x, 8.2
版本: 8.1.x, 8.2 (对8.3也是合适的，译者注)
Platform: NT, Win 2000
平台: NT, Win 2000
Cause: NA
故障原因: 无
Answer:
答案:
The following steps reset the environment variables and registry in order to do a clean installation of ArcGIS 8.1.x and 8.2.
下列步骤将初始化环境变量及注册表，然后进行全新的ArcGIS 8.1.x或8.2的安装。
1. Uninstall ArcGIS Desktop and Workstation versions (if applicable) by clicking Start > Settings > Control Panel. Double-click Add/Remove Programs.
1.点击开始>设置> 控制面板，双击添加/移除程序， 卸载ArcGIS desktop和Workstation版本(如果有的话)。
2. Reboot your machine.
2. 重启您的机器
3. Place ArcGIS Desktop CD in the CD-ROM drive.
3. 将ArcGIS desktop 光盘插入光盘
4. Cancel out of the Auto-Install window.
4. 取消弹出的自动安装窗口
5. Click Start > Run.
5. 点击开始> 运行
6. Type this command : <cd-rom drive letter>:"setup /cleanup
6. 键入下列命令: <光盘盘符>:"setup /cleanup
7. Make sure you type a space character after the word setup.
7. 确保您在单词setup之后有一个空格字符
8. Click OK to start the process.
8. 单击OK开始运行
9. Reboot and log back in as a user with administrative privileges.
9. 重起并以一个具备管理员权限的用户登录进机器
10. Remove and insert the CD again to start the autorun and install ArcGIS Desktop.
10. 弹出并再次插入光盘，开始光盘自动运行并安装ArcGIS Desktop
11. Install ArcGIS Workstation (if applicable) by placing the Workstation CD into the CD-ROM drive.
11. 如果需要的话，将ArcGIS Workstaion光盘插入光驱，安装ArcGIS workstaion。
12. Don't do a cleanup with this CD.
12. 不需要ArcGIS workstation光盘再次执行清理工作。
13. Reboot and log back in as a user with administrative privileges.
13. 重起并以一个具备管理员权限的用户登录进机器
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