In addition, and as a final remark on my behalf (it is time to get back to my real studies, though it was fun and reminded me to the time of 2005 where I was one of the minorities who bought xp x64 and where often forced to get used to modify .msi's with Orca) - I tried it again with the (official technet) sysprep way... the reason why WinToolkit recognized my first preped image as being corrupt was that I have chosen a custom name for the image.... still now, and after I've named it right, and though simply building a .iso via WT from the syspreped .wim worked like a charm (the get-package information afterwards was the same as for a real sp1 install-media), it failed when I tried to integrate IE11 and its prerequisites. That doesn't worked out well - WT integrated fine, the install resulted in failures which may well be searched in this forum for the early times of IE11 and its integration. So i am not sure if I missed some KB or if it ain't be possible to use WT on a syspreped .wim (which makes no sense IMHO, so my guess would still be a fault in my procedures - and that one may include that I where using a WinPE.iso handed over to the VM that where build with the current ADK release for Win8+; I used that because it is much easier to apply the dism commands (/capture-image) to build the .wim then using the old variant with imageX). As said, I still think that it is possible (else all technet sysprep how to build an oem/multilingual media, how to deploy sp1, etc. descriptions wouldn't make sense; At least for the sysprep way). In the meantime where the vm(s) where occupied with their install I checked the MD5 sums of the KB976902 files with their corresponding parts of KB976932 (SP1) and there where no differences to be found (haven't checked all of the files), so it should - in theory be possible - to get along that way to a working (and future proof) image... But as the OPs question (OEM based Win 7) and my curiosity about Dreamsparks PreSP1 Server 2008 R2 .img are just a minority in cases that may be neglected in the development of WT (or the Foolproof assignments/modules therein (which in my experiences make up 3/4 the time in the development of a GUI based project)) I just give up with trying any further (and will continue with my real work/study again ).