Typically, the culprit for something like that is either the audio interface or the network/wifi card. Unless you have a very old nVidia (pre-series 5, but as far as I remember, the 210 isn’t that old), I would exclude issues with the GPU.
You might want all AERO on to see if that solve the problem.
Best regards
Freddie
With your hdspe what Adat clock are you using ?
Ive found with my RME if im using the internal clock of the RME and not the source clock im always getting clicks and pops . … you never know 
I"ve found in the past some Nvidia drivers can be a little flaky with Cubase. Disabling temporarily and running on windows default video driver will tell you if thats where you should be looking.
I had this when I updated my BIOS firmware, after disableing Hyperthreading and some eco settings regarding powerusage the pops went away.