DpInst
Driver installer using Dpinst.exe more info about dpinst.exe can be found here: http://msdn.microsoft.com/en-us/library/ff544842%28VS.85%29.aspx
<?xml version="1.0" encoding="UTF-8"?>
<packages>
<package id="dpinst"
name="DpInst driver installer"
revision="3"
execute="once"
reboot="false"
priority="0">
<install cmd='%software%\tools\driversigning\DriverSigning\DriverSigning-Off.exe' />
<!-- temporary disable driver signing check -->
<install cmd='pathto\dpinst.exe /S /PATH \\server\driverrepo\' >
<!-- install drivers and allow any exit code as -->
<install cmd='%software%\tools\driversigning\DriverSigning\DriverSigning-On.exe' />
<!-- re-enable driver signing -->
</package>
</packages>
to get DriverSigning-Off and -On .exe check OpenVPN page
Ensure that you put only driver related files in to the driver repo directory (for example .inf .sys) it will install any driver found in driverrepo directory, however subdirs are not supported at the moment.