I've written a custom action in my Microsoft Systems Management Server (SMS) OS Deployment Feature Pack deployment that modifies the sysprep.inf file with an updated OemPnPDriversPath. Why is the action having no effect?

A. Normally, you can use the OemPnPDriversPath value to instruct the Setup Wizard to check other locations for drivers for detected hardware. However, if you set this value in the post-installation phase of an SMS OS Deployment Feature Pack deployment, in some circumstances this is too late and will have no effect. Instead, you need to edit the DevicePath registry key on the deployed OS and set the full list of driver path folders. The following code performs this action:

reg load HKLMsw %OSDTARGETDRIVE%windowssystem32configsoftware reg add HKLMswmicrosoftwindowscurrentversion /v DevicePath /t REG_EXPAND_SZ /f /d "c:windowsinf;c:driversetwork;c:driversstorage;c:driversVideo" reg unload HKLMsw 

The second line performs the actual modification to the DevicePath variable and sets it to search the default c:windowsinf folder and any additional driver folders. You'd add this code as a post-installation phase action.