Software Deployment

I have extracted the Silverlight MSI and MSP from the exe, and have created a transform using Wise 7 to disable auto updates and followed instructions from here

Upon installation for the package, Microsoft tries to call http://go2.microsoft.com/fwlink-?prd=12603&pclID=0x409&2r=UPDATE&sar=AUTO&prev=

I opened up the patch over the msi using orca and found the msp contains a property "SILENTUPGRADE=0". Is this the property which is allowing a call to search for updates? Is it possible that this property is overwriting the AUTOUPDATEDISABLE=1?