Slightly late....but if anyone stumbles on this and needs some help......
A range of Microsoft drivers are actually delivered in Service Packs and Hotfixes. They do not, necessarily, have a matching *.inf file. IntelPPM.SYS is an example of this. In many cases, the driver files are bundled as part of a group, together with a single *.inf file that covers the range of *.sys files. In other words the name of the *.inf file may not match the name of the driver.
There are 3 ways to find the matching *.inf file:
(1) Search for the name of the driver (in this case IntelPPM) and look for the corresponding *.cab file. You should then be able to unpack the cab and find a suitable *.inf in there, albeit with a different name. If there is only one *.inf file it's easy.
(2) Search through the registry for "IntelPPM". In many cases there are will a key that marked with something like "InfPath" and it will list the corresponding *.inf. In your case, the matching *.inf file is:
C:\WINDOWS\inf\cpu.inf
(3) Run a search against the C:\WINDOWS\inf\ directory, looking for the driver name INSIDE the file.