Repair Site

Troubleshooting Flash Player Error 1721

Flash player error 1721 is a very common and very frustrating error that is the result of multiple conditions.  Users that are experiencing Flash player error 1721 will have to undergo a fair bit of troubleshooting before a resolution may be put into place.  Error 1721 may crop up at any number of times, though the most common time is during the installation of Macromedia Flash.

This error is not unique to Macromedia Flash and may happen during regular operation/installation of other programs on your computer. 

Background Information about the Flash Player Error 1721:

Specific error name: Error #1721: There is a problem with this Windows Installer package.  A program run as part of the setup did not finish as expected.  Contact your support personnel or package vendor.

This error may arise when using the "add/remove programs" menu in Windows XP/Vista, or when using a typical installation package that comes with a program.  This error occurs because the Microsoft Installer doesn’t have permission to access the necessary folder locations, or something is damaged/corrupt, or something is out of date with the installer.  Any one of those will cause error 1721.

Fixing Flash Player Error 1221:

Before trying anything invasive, try uninstalling and then reinstalling Flash.  Many people will attempt to uninstall Flash by simply deleting everything in the folder, leaving registry settings and shared files intact and resulting in a very messed up Flash installation.  The only proper way to remove Flash is to completely remove it via the Adobe uninstall tool.

Follow the steps below to uninstall and reinstall Flash:

• Uninstall Flash via the Adobe uninstall tool - Found here (http://kb2.adobe.com/cps/141/tn_14157.html), this tool is the only way to completely remove Macromedia Flash from your system.  Choose the version that is appropriate for your operating system, download, and then run the program.
  
  Once the program has run it will have completely removed Flash from your computer.  You can verify this by trying to visit any Flash-enabled website.

• Reinstall Flash - Once Flash has been completely uninstalled, reinstall Flash by visiting the Adobe Flash website (http://www.adobe.com/products/flashplayer/).  Be sure to download the latest version (as of this writing it was version 10).

If the complete uninstall still throws error 1721 when trying to reinstall Flash then you will have to deal with Windows directly to solve the problem.  Follow the steps below in order.

1. If using Windows XP, reregister the Windows XP Installer service - Instructions on how to do this properly can be found at http://support.microsoft.com/kb/891985 under the subheading "Reregister the Windows Installer Service".  Be sure to complete this step if you are using Windows XP (all versions).  Ignore this step if you are using Windows Vista.

2. Launch the Microsoft System File Checker - Follow the instructions on how to do this properly at http://support.microsoft.com/kb/891985 under the subheading "Run System File Checker".

3. Update the temp directory user privileges - When installing programs the installer package creates a temporary directory to unpack the compressed files into.  If the installer doesn’t have the appropriate permissions it will be unable to complete the installation process and throw an error 1721. 
   
   You can update the properties of the temporary directory, eliminating any permissions issues.
   
   Using Windows XP:

• Open your "local settings" folder - This is typically found in "c:\documents and settings\<user name>\Local Settings.
  
• Right-click the temp folder and select "properties"- Once you’ve clicked properties, select the "security" tab.
  
• Select "Administrators" from the "Groups or user names" tab - Place the permissions of "Full control" to "allow".
  
• Select "SYSTEM" from the "Groups or user names" tab - Place the permissions of "Full control" to "allow".
  

• Then click the "advanced" button - Here, select the checkmark for "replace permission entries on all child objects with entries shown here that apply to child ojects."
  
  Click yes on the resulting security box.

Using Windows Vista:

• In Windows Explorer, open your temporary folder - This is usually found in "c:\users\<user name>\AppData\Local
  
• Right-click the temp folder and select "properties" - Then select the "Security" tab, then click "advanced".
  
• Select the "owners" tab - Then click "edit".
  
• Select the "administrators" group under "change owner to" - Check the "replace owner on subcontainers and objects".  Then click "ok" to close the advanced window, then click "ok" to close the temp properties window.
  
• Right click "temp" and select "properties" - Then select the "Security" tab and click on "advanced".
  
• Select the "permissions" tab - Then select "edit".  Verify that the permissions column for "SYSTEM" says "full control".  If it doesn’t, select SYSTEM and then click "edit".  Select "full control" and click "ok".