When I work in Houdini I experience somewhat random short freezes of 1~2 seconds. It mostly happens when I add or delete nodes, even if that node is not connected to an active network…
It's not a showstopper but it's annoying and breaks the flow.
I think I didn't experience this when I first downloaded Houdini a few weeks ago.

My System
Houdini Indie
Windows 10 Pro 64bit
Intel i7 4770k
16GB ram
nvidia GeForce 1060 6GB (latest drivers updated today)

Any ideas how to fix this?

check that the RenderView isn't doing an IPR rendering.

Have a look in the Taskmanager, is your system memory running out of space? Are there any CPU-hogs? (processes, using up all your CPUs for no apparent reason)

Disconnect the internet and check if the issue persists. I had a similar issue because my firewall was blocking some connections. After allowing Houdini in my hosts file it solved the freezing.