I have created a new, second x86 boot image which has a number of tweaks, but which I dont want to use for all devices, just some for testing (its not signed off yet). However, when I boot one of the test machines to test the different TS with which the new boot image is associated, it still uses the original boot image, downloads the new boot image and then prompts to click OK before restarting into the new boot image in order to start the TS. How do I choose which x86 boot image is the active one? As a side question; This seems very odd, in order to decide if a machine can PXE boot or not (abort) it is dependant on querying the SCCM DB, therefore the choice of boot image can also be queried by looking at the TS? Is this just poor planning from MS? Is there a better system in 2012?

See this post - http://social.technet.microsoft.com/forums/en-US/configmgrosd/thread/3c5db41b-efb6-49d3-8a21-6b2341edcc8a/ I think most people have had success with simply using one x86 boot image for all systems. Once you've chosen an advertisement, if the PE is different, it gets downloaded and staged at that point. As for which boot image gets used for initial boot where multiple applicable boot images exist, most get the boot image from the last TS advertised. There's more detail in the post above. I've used the info successfully myself.

When using multiple non-mandatory adverts though, there is no way for it know which TS you are going to choose. The only way it can know which boot image to use is if you have a single mandatory TS advertised to the system. Technically the behavior is undefined meaning that this behavior was not specifically in the design document and is not guaranteed to exist in future versions. The actual behavior though is that the advert with the highest ID is used when deciding upon a boot image when multiple adverts are possible. This may be arbitrary, but there simply is no other way to know because the TS is still in doubt. The behavior does not change in 2012 (very little in OSD does).Jason | http://blog.configmgrftw.com | Twitter @JasonSandys

When using multiple non-mandatory adverts though, there is no way for it know which TS you are going to choose. The only way it can know which boot image to use is if you have a single mandatory TS advertised to the system. Jason | http://blog.configmgrftw.com | Twitter @JasonSandys  So mandatory TS's will work and allow multiple boot images - I suppose this points back to having a script to remove a device from a collection at the end of a task sequence. That seems so messy to me, at the very least there should be some sort of built in script specifying the collection to remove the device from, even if its an MDT style add-in to the built in OSD actions. How difficult/easy would it be for someone (by someone i mean a member of this forum who knows more than me!) to write one of those?

As for which boot image gets used for initial boot where multiple applicable boot images exist, most get the boot image from the last TS advertised. Thats helpful, thanks. At least there is some logic behind how one is chosen.

When using multiple non-mandatory adverts though, there is no way for it know which TS you are going to choose. The only way it can know which boot image to use is if you have a single mandatory TS advertised to the system. Technically the behavior is undefined meaning that this behavior was not specifically in the design document and is not guaranteed to exist in future versions. The actual behavior though is that the advert with the highest ID is used when deciding upon a boot image when multiple adverts are possible. This may be arbitrary, but there simply is no other way to know because the TS is still in doubt. The behavior does not change in 2012 (very little in OSD does). Jason | http://blog.configmgrftw.com | Twitter @JasonSandys Thanks Jason... this clarifies everything. I was told by an unnamed professional that the most recently advertised boot image takes precedense.. Which you can kind of see how they can draw that conclusion because newer adverts have higher advertIDs. However, I was told that if I make a non-change to the advert and click "Apply" then it would set that particular Advert to take presedence... which I have spent days scratching my head trying to get to work. With this knowledge, I can work with this.. I just have to recycle old adverts :)