Doing a manual update for TurboTax Desktop should resolve Microsoft Installer Error:1603.

Please follow the directions in this TurboTax Help Article: Manually Update TurboTax for Windows Software

I am using TT desktop and getting the same error 1603.  Manual update didn't work.

Thank you.

You need to clear your Cache and Cookies before doing the manual update.

What is a manual update?

Thanks for your reply.

Actually, the error message I am getting is: Microsoft Installer error 2725.

Thanks again for your help!