QuickBooks error 1603 is associated with the installation or update process. To fix this error, the users can implement the steps that are mentioned below
 In your operating system, you need to download and install QBInstallTool.exe file with the file size of 648 KB.
 Next, you can also start the MXSML installation process after inserting the QuickBooks CD into the system
 The users can also run the QuickBooks Diagnostic tool in the PC
And if none of the solutions proves useful, then one should immediately get in touch with Quickbooks customer service number