I've never heard of CPU drivers before.

For a while AMD had processor drivers, but I think that had to do with the first processors that didn't 'show' their speed, just a 'rating'. Windows didn't read the rating (just the frequency, which would look low), so AMD released a driver that would just change the way it showed in the Windows device manager.

Since then Microsoft has just implemented a different way to show the processor in the device manager and I haven't seen processor drivers since then.

There are chipset drivers that run some chipsets on the motherboard. Dell doesnt use any processor drivers, and I have never heard of one.

 

Any "cpu" drivers are always included in the OS default,basically (coded in) they dont exist to an end user. AMD did have AMD drives, but they were more to fix specific issues and werent always need to work.