Run the DPC latency checker, now, before you install any applications and see what it reports.
+20
That's great advice.
Back when I couldn't get my Tascam interface running on my old XP laptop I did that. I started clean like your doing, new OS install. The first thing I did after OS was run DPCLAT meter. I took a screen shot of that and the Task Manager Process running screen.
I did the same between each driver and then software install.
The most interesting thing I found was the minute I turned the Tascam interface on, DPC would jump 150ms to 200ms??
I tried my M Audio interface and this did not happen.
Wireless and battery monitor sent it through the roof.
Don't activate the camera if your not using it because that was another one that made a jump on mine.
What I found out was the majority of running processes made very little if no difference at all to the DPCLAT readings. There's only a few well known to be avoided.