Solution to Uninstall Error 1721

When you try to uninstall a program using Add or Remove Programs utility in Microsoft Windows XP computer, you may encounter the following error:

“Error 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personal or package vendor.”

Resolution Method

To resolve the uninstall error 1721, unregister and then re-register the Windows Installer Service and then try to uninstall the program. If you still get error, you need to run the System File Checker (SFC) command.

Steps to reregister the Windows Installer Service

On a Windows computer, the Windows Installer Service manages the uninstallation and installation of programs. If the Windows Installer service is incorrectly registered or if its registration information is corrupt, you may not be able to uninstall programs that you have installed using Windows Installer.

Perform the following steps to unregister and reregister the Windows Installer Service:

  1. Restart your computer and press F8 after the BIOS information is displayed.
  2. Next, use the arrow keys to select the Safe Mode option and press Enter.
  3. Log on to your computer as Administrator.
  4. Next, click Start and then click the Run command.
  5. Type the cmd command in the Open box and press Enter.
  6. At the command prompt type the following command and press Enter.
    msiexec u/unregister
  7. Next, at the command prompt, type the following command and press Enter.
    msiexec /register
  8. Now, type exit and press Enter to quit command prompt.
  9. Click Start and then select Control Panel.
  10. Double-click Add or Remove Programs to open its corresponding window.
  11. Locate and select the program you want to uninstall and then click the Remove button.

If the error persists when you try to uninstall the program, then perform the steps illustrated in the next section.

Steps to run the System File Checker (SFC) command

The System File Checker is a command-line utility that scans the protected operating system files to check their version and integrity. In case the System File Checker finds any protected file to be damaged or of an incorrect version, it replaces the damaged file with a file that has correct version from the cache folder or from the original Windows Installation CD.

To run System File Checker, perform the following steps:

Note: To run the sfc command, you need to log on as an Administrator. Also, you may be prompted to insert the original Windows XP Installation disc. Ensure that you have your Windows XP installation disc with you before you run the sfc command.

  1. Click Start and then click Run.
  2. Type cmd and press Enter.
  3. Next, at the command prompt, type sfc /purgecache and press Enter.
  4. After the above command is completed successfully, type sfc /scannow at command prompt and press Enter.
  5. Next, type exit and press Enter to close command prompt.

After you have successfully performed the above steps, uninstall the program using the Add or Remove Programs utility.

If you still face difficulties or if you find the above steps quite complicated, it is best to opt for a reliable program removal tool, such as Perfect Uninstaller. Using this tool, you can easily force an uninstall of a program that you are unable to uninstall using other methods.