It's probably not lag as thats usually server based or something to do with your internet connection... which hyper cam doesn't use.
Now i think its more to do with the specs of your PC, its too much for it to handle but if you want to record i recommend closing everything you don't need which frees up some CPU and memory usage.
Press CTRL+ALT+DEL and close all the process you do not need THIS INCLUDES EXPLORER.EXE, YOU DONT NEED IT!!! If you close explorer it removes the start bar, icons and basically everything, to get it back just do this...
CTRL + ALT + DEL -> File -> New Task (Run...) -> Type in "explorer.exe"
The above bring back start menu/bar/icons/background...