I had the problem with hearthstone occasionally freezing for 2-3 seconds and not responding for that period. At first, I thought it was a problem with hearthranger but this solution seems to have fixed it for me:
1. Hit Windows Key + R (or just load the run prompt, however you want to do it)
2. Type %localappdata% (this will load your "local" appdata folder, the exact path is different depending on your computers username)
3. Open the "Blizzard" folder inside the "Local" folder you are currently in.
4. Delete the "Hearthstone" folder.
You will lose your heartstone settings, but there are few configurable settings like windowed vs non-windowed that you would want to change. This helped tremendously with my problem.
If you decide to make the folder "read only", make sure you run the game at least once so that it can create a new folder for appdata, then make it read only so that the folder never actually collects all the garbage you don't want.
Making the folder read only before deleting it only ensures that the problem will stay exactly as it is, and get no worse. However, if you delete the folder first and allow hearthstone to create it fresh, I would see no problems with making it read only after that.
Make sure you get your settings the way you like them before you make the folder read only though.
