So you want to add the $OEM$ folder to your SCCM 2007 OS Deployments?
Well, if you just add the $OEM$ folder to the package (any location) it will be skipped… The reason is because the “Setup Windows and ConfigMgr” action adds (or overwrites) the OemFilesPath=C:\_SMSTaskSequence\OSD\$OEM$ value in unattend.txt before starting Winnt32.exe
The workaround is simple. Just copy your $OEM$ folder to C:\_SMSTaskSequence\OSD as a Custom Action before the “Setup Windows and ConfigMgr” (You will have to create the OSD subfolder in C:\_SMSTaskSequence first)
If you add a well formatted cmdlines.txt file to C:\_SMSTaskSequence\OSD\$OEM$ it is smart enough to merge your cmdlines settings with its own settings (the OSDSETUPHOOK.)
If you need a sample script for copying the $OEM$ directory, check out this nice entry
Can you use $OEM$ Files with SCCM 2007 OS Deployments?