Error 123 is displayed when using TurboTax 2010

To resolve this issue:

1. Click here to obtain the .NET Cleanup Tool and then click the "zipped folder" icon to download the tool. Save the zipped file on your desktop.
2. Close all browser windows and programs.
3. Double-click the dotnetfx_cleanup_tool.zip file on your desktop to open it.
4. In the opened .zip file, double-click cleanup_tool.exe to run the tool.
   • Windows XP: Clean up .NET 3.5 – .NET 3.0 – .NET 2.0, in that order.
   • Windows Vista: Clean up .NET 3.5.
   • Windows 7: From the Windows Start menu, type cmd in the Search programs and files field and press Enter.
     • In the black cmd.exe window, type sfc /scannow (include a space after sfc) and press Enter.
5. Restart your computer, and then install TurboTax.

If the problem persists, you'll need to reinstall Windows Installer 4.5.