If your options are the same, one file should work. In your case, you could potentially have 2 different keys, which might be an issue. I use one file for both my x86 and x64 installs. I did have to create one for each, and then I merged them. Does that help? Here is a quick example: <?xml version="1.0" encoding="utf-8"?> <unattend xmlns="urn:schemas-microsoft-com:unattend"> <settings pass="specialize"> <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="x86" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <ProductKey>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</ProductKey> <TimeZone>Eastern Standard Time</TimeZone> <DisableAutoDaylightTimeSet>false</DisableAutoDaylightTimeSet> </component> </settings> <settings pass="specialize"> <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <ProductKey>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</ProductKey> <DisableAutoDaylightTimeSet>false</DisableAutoDaylightTimeSet> <TimeZone>Eastern Standard Time</TimeZone> </component> </settings> <cpi:offlineImage cpi:source="wim:v:/slipstream/windowssevenenterprisecombined/sources/install.wim#ENTERPRISEX86" xmlns:cpi="urn:schemas-microsoft-com:cpi" /> </unattend>