Originally Answered: I can't watch videos on youtube?
1. Uninstall all previous versions
Before you install Flash Player for any Windows browser, uninstall all previous versions. For instructions on removing the player, please see "How to uninstall the Adobe Flash Player plug-in and ActiveX control" (TechNote 14157).
Note: All applications must be closed before you run the Flash Player uninstaller. Quit all running applications, including all Internet Explorer or other browser windows, and all Instant Messenger clients. Check the Windows system tray carefully to make certain no applications which might possibly use Flash Player are still in memory.
After you have removed previous versions, you are ready to download and/or install Flash Player.
2. Download Adobe Flash Player
Flash Player is available for download from the Adobe Flash Player Download Center.
3. Troubleshoot Adobe Flash Player for Internet Explorer
Before installing Flash Player, please check the following browser settings:
Internet Explorer ActiveX settings
Browser security settings should be chosen by you or by your system administrator. For single users who do not have an administrator, the Medium: Default Level allows you to view Flash content. For any Custom Level, ensure that both the "Download Signed ActiveX controls" and "Run ActiveX controls and plug-ins" options are set to "Prompt".
To change your security level:
1. Open Internet Explorer.
2. Choose Tools > Internet Options.
3. Select the Security tab.
4. Select Custom Level.
5. Find the section "ActiveX controls and plug-ins".
6. Set ' Download Signed ActiveX Controls' to Prompt.
7. Set 'Run ActiveX Controls And Plug-ins' to Prompt.
If you are having trouble installing, make sure that your Internet Explorer security level is not set to High or to a custom level that does not allow viewing of ActiveX controls.
A damaged Windows system registry or incorrect permissions in the registry may prevent Flash Player from installing or registering correctly.
Symptoms of a damaged registry or incorrect permissions may include:
* Error during Flash Player installation:
'Failed to install. For Troubleshooting please see: http://www.adobe.com/go/tn_19166'
* Flash Player installer finishes with no error, but Flash content cannot be viewed in Internet Explorer.
* Some sites tell you that you do not have the correct version of Flash Player, even though you just installed the latest version.
* Some sites tell you to reinstall Flash Player, but after reinstalling the same message occurs.
Download SubInACL from Microsoft to fix permission issues that prevent the Flash Player installation. For instruction on how to run SubInACL to fix these permission issues please refer to "Download SubInACL from Microsoft to fix permission issues that prevent the Flash Player installation" (TechNote fb1634cb).
Windows Vista installation failure
On some Windows Vista systems Flash Player may be installed, but will not display Flash content. In some cases updating to the latest Flash Player using the included utility can correct the User Account Control settings that cause this problem.
To run the utility, find your installed Flash folder:
* Right-click C:\Windows\System32\Macromed\Flash\Flash...
The letter changes with each Flash version, so may be "FlashUtilb.exe" or "FlashUtile.exe"
* Select "Run as Administrator"
* Follow the steps to complete the Flash Player installation
* Restart your computer
Computer user permissions
User permissions determine whether or not you are allowed to install ActiveX controls or plug-ins. If you don't have Administrator access to Windows NT, 2000, XP, or Vista you may not be able to install Flash Player successfully. Administrative privileges are required for the Windows system registry and for the C:\WINDOWS\system32\Macromed\Flash folder.
Error while installing older version: The version of Adobe Flash Player ActiveX that you are trying to install is not the most current version
If you previously installed a later version of Flash Player for Internet Explorer, you may be prevented from installing an earlier version. For example, if you installed Flash Player 9,0,115,0, and attempted to install version 9,0,47,0 the installation would fail. In this case follow the instructions in "Safe versions security restrictions when installing Flash Player" (TechNote kb402435).
If the ActiveX Control for Flash Player fails to install, download the executable installer.
If the information above has not resolved the issue, download the executable Flash Player installer here:
* Download and unzip Install_Flash_Player_9_ActiveX.zip.
Save this installer to your desktop, close out all applications, and run the installer. This may help if you are having trouble with the ActiveX installation from Adobe.com. To confirm that Flash Player has installed successfully, please visit: www.macromedia.com/s