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Here are a set of steps you can follow to use Windows Installer command line parameters to create an installable layout that includes the .NET Framework and a service pack:
- Download the .NET Framework 1.0 or the .NET Framework 1.1
- Extract the contents of the .NET Framework to a folder - you can do this by running dotnetfx.exe /t:c:\temp /c (where c:\temp is any folder of your choosing)
- Download the .NET Framework 1.0 SP3 or the .NET Framework 1.1 SP1
- Extract the service pack MSP package to a folder by running .exe /Xp:c:\temp\ndpsp.msp
- Run msiexec.exe /a c:\temp\netfx.msi /p c:\temp\ndpsp.msp TARGETDIR=c:\temp
Following these steps will create an MSI and a set of files in the folder c:\temp that can be used to install the .NET Framework and a service pack.
Source: Creating a combined install point with the .NET Framework and a service pack