We recently migrated 5 2007 sites to a single ConfigMgr 2012 site. All is well except technicians now see advertisements to unknown computers that do not pertain to them. I need to taget specific unknown machines and make task sequences available to just those machines. I have 5 groups barking about how they used to have their own site and I HAVE SEEN PEOPLE SAY THIS IS IMPOSSIBLE. so before you instinctively shoot this idea down, hear me out.....

Make One Single task sequence to available unknown machines. This task sequence is solely responsible for collecting task sequence variables from the technicians. once the data is collected, a small task sequence will run and hopefully create a computer record in sccm with the data specified by that technician in the task sequence wizard.  This data will make the computer available to a collection with the specific groups' task sequences only available to it.  It is a bit convoluted but if it wasn't that serious I wouldnt be here posting about it.

Also I think there may be something to the prestart commands on the boot media to narrow down the set of task sequences available to an unknown computer. 

Another downer is the drop-down category box that was available in Run avertised programs in 2007. Something like that would probably help but I have not seen anything of the sort in 2012 from the task sequence wizard interface.

Has anyone got something like this to work or am I chasing my tail?

Have you integrated MDT (MS Deployment Toolkit)? It can be used to automate "things". It can dynamically populate variables depending on location, made/model, MAC, etc ... that *might* solve your problem, too.

We did not integrate mdt but looking and I was hoping to keep our 2012 enviroment sterile of alot of the add ons. in 2007 we had polluted it with several add-ons that we never used. So consequently I have been reluctant to install any in our 2012 environment. Reading up on the MDT documentation I am struggling to see where MDT integration would provide a solution for this scenario.

In the 2012 sp1 native environment I can already enter task sequence variables but these tend to be more for configuration during a task squence and not for collection membership or targeting

I don't use MDT myself, but perhaps the UDI feature might be helpful:

https://blogs.technet.com/b/chrad/archive/2012/07/26/learning-mdt-2012-s-user-driven-installation-udi.aspx?Redirected=true

What i understood is that your technician should be seeing only specific task sequence on a specific set of unknown computers. Lets suppose you have 5 scenarios of unknown computers, each has got a specific ts variable. Now create 5 collections and set the variables on the collections. Yes use collection variables rather than ts variables. Now give a simple script or HTA to your technician to import the computer to Sccm along with MAC and then add it to specific collection. Target only one ts on each of these collections. The scripts to import and addtocollection are already available in SCCM SDK, but if you want I can post them here. Hope this helps. Regards, Manohar Pusala

As the others have eluded to unknown computer are all unknown computers. If you want to limit what people see when they boot an unknown computer you will have to do something other than the out of the box behavior.

On a second note: I strongly reccomend you integrate MDT. I don't even consider it an "add on" because the MDT team and configmgr team internally at MS are now one team.

unfortunately we do not have the computer information to import until it touches sccm. Had this been the case we could easily accomplish this by making static collection with imported information. computers are stored and may be used by any one of 5 groups so we would not be able to accomplish this. 

Im not closed off to the idea of adding mdt. but as I stated earlier, no matter how sexy mdt looks, I struggle to find where it will help me accomplish this particular task. Unless Im missing something, please let me know how MDT will help. 

Personally I'd tell the whiny techs they are just gonna have to pick one of the 5 TS's. Or better yet, get the 5 down to less. Why do you need 5?

It may or may not help in this particular scenario but it will help in your overall OSD strategy. UDI could be an option to help you in this scenario but it has it's own set of problems.

As Torsten said... It's possible you could set a variable based off the IP of the machine that could help in this scenario. I've never done it but it may be worth investigating.

LOL. I couldnt have said it better myself. LOL!

Each TS is created by a different group, in a different ou, at a different site,  and the TS have settings specific to the group that manages the computer....trust me I've tried to smoosh them together. Im working with techs that flip out when 1 additional thing shows up in the list. "I used to pick the second option in the list, now there's 3 to choose from!" No reading just mindless clicking. LOL. Also, I was a big fan of one site and I was hoping to make as seamless of a transition as possible. 

But breaking the news to them is plan B. I was hoping to avoid it if I could.

I feel your pain. This is getting into political advice not technical and I understand you didn't ask for that so take it for what it's worth...

I'd go over their heads. Go to management and show them how much $$$ they can save by centralizing the imaging process. One TS for all groups. You can control the OU and all that other stuff very easily with variables. The standardized environment will cut cost dramatically.

In the mean time just smack the guys in the head. :-)

when we rolled out 2012 15 servers became obsolete so everyone is well aware of how much we saved. Even for me its less to manage by integrating sus and scep. so far this work around is the only hurdle and it will likely not be well received but i wanted to at least try to make it work. 

Is there any technical parameter (gateway, AD site etc) that can be used to determine which task sequence should be executed?

 gateway is an excellent determining factor but I cannot figure out how to target based on that info.  is there a  way to use the gate way  of an unknown machine to determine task sequences for a computer.

Yes, MDT can do that. "Locations" (an object in MDT which uses the default gateway) can be used to specify a set of settings (which apps to install, which domain / OU to join and a lot more). You would have to consolidate the contents of those 5 task sequences into a single MDT one (which still is extremely flexi

I spent a few days looking into this and the way that i will have to implement MDT will not be practical. Each of the group frequently changes the task sequence so with 1 task sequence i now have way too many hands in thee cookie jar amd no way to log who changed it. To make it worse cm12 removed the specific usernames on status messages to see exactly which user implemented a specific cm task, what gives.  However this solution may come in handy for something else down the road.

for now Im looking into the prestart commands with hidden task sequences which look promising.

 http://blogs.technet.com/b/keithmayer/archive/2013/02/06/5-steps-to-deploying-windows-8-with-system-center-2012-service-pack-1-part-3-of-19.aspx

The hidden option above allows you to deploy the task sequence so that it doesnt show up in the selection list in the Windows PE boot environment.  If using this option, you can specify this deployment by setting anew task sequence variable, SMSTSPreferredAdvertID, to the value of the Advertisement ID for this deployed task sequence as part of a prestart command in your Boot Image Properties.  See How to Set an Operating System Task Sequence Variable for more details on creating a script to set a task sequence variable value.