1、下載反安裝程式於桌面
windows: 
http://download.macromedia.com/pub/flashplayer/current/uninstall_flash_player.exe

mac os 10.3以上: http://fpdownload.macromedia.com/get/flashplayer/current/uninstall_flash_player_osx.dmg

mac os 10.2以下: 
http://download.macromedia.com/pub/flash/ts/uninstall_flash_player_osx_10.2.dmg 

mac os  8.x,9.x  : 
http://download.macromedia.com/pub/flash/ts/uninstall_flash_player.hqx

2、關閉所有已開啟的應用程試 

3、啟動反安裝程式

4、前往adobe安裝flashplayer    
http://get.adobe.com/flashplayer/ 

* 如有遇到移除後無法再安裝之狀況(Microsoft to fix permission issues):

1、下載 SubInACL (SubInACL.exe) 
http://www.microsoft.com/downloads/details.aspx?FamilyID=e8ba3e56-d8fe-4a91-93cf-ed6985e3927b&displaylang=en

2、安裝SubInACL

3、下載 reset_fp10.zip
 http://www.adobe.com/support/flashplayer/ts/documents/fb1634cb/reset_fp10

4、解壓縮 reset_fp10.cmd 到 C:\Program Files\Windows Resource Kits\Tools\

5、雙擊執行reset_fp10.cmd使之執行

6、當執行時請勿使用電腦

7、當他完成時會出現”Press any key to continue”(請按下任意鍵繼續)

8、前往adobe安裝flashplayer   
http://get.adobe.com/flashplayer/

參考文件內容: 

How to uninstall the Adobe Flash Player plug-in and ActiveX control:
http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_14157&sliceId=2

Download SubInACL from Microsoft to fix permission issues that prevent the Flash Player installation:
http://kb.adobe.com/selfservice/viewContent.do?externalId=fb1634cb&sliceId=1