Ok here's what you do:
Desktop / Laptop:
1) Extract the .cab or .tsk to a folder on your computer. So you should have all the files in a folder.
2) Download WinMerge (awesome utility for many other things other than what I'm going to use it for)
www.winmerge.com
your device:
3) Export your registry to a file that can be converted to a txt. On my Titan I use PHM RegEdit to export into a rbk which can be read as a txt.
4) Now install the .cab on your device
5) Export your registry again and send it to your desktop
6) Use the search program and do a search for the files that you got from step 1. This will give you the folder names that these files should be stored in.
Back on your laptop/desktop
7) Open OEMizer and drag those files into the box
Assign those files to the proper folder based on what you found out on step 6.
9) Go into winmerge and compare the registry dumps from step 3 and step 5 to each other. It should then highlight every section where the two vary.
10) Copy those missing registry sections (in the correct syntax) to the registry box in OEMizer
Those 10 steps make it sound pretty easy but it's sometimes a long process. This is the whole reason why I have created this thread is because converting the registry keys to the right syntax is hit or miss, and for some of the small cabs that I have OEMized it's easy to just play around with it until I get it right. For the large ones (SPB Backup) has 28 entries it takes me longer, but I can just about convert any .cab. Someone helps me with converting the registry entries and I can do any .cab someone throws at me.