Hi! Do you resolve this error? i have the same error, do you have the command line? Thanks!!! kvarga wrote: Installing "Microsoft SQL Server 2008 Express SP1 (x86 & x64Wow)" prerequisite fails on 64 bit machine unless I specify /X86=1. The /X86 option is not valid for a 32 bit OS. I need to be able to install our 32 bit application on both 32 bit and 64 bit OS machines. This works as long as I specifiy the /X86=1 in the command line when running on 64 bit OS ( Windows 7 in this case) and not specify it when on a 32 bit OS. First, am I missing something? If I need to specify it, how do I add it to the command line parameters for the prerequisite when running on a 64 bit OS and not add the parameter when on a 32 bit OS? Keith ... View more