it should be to do with the buffer size....i think you need to increase it for smoother performance but it uses more CPU sooooo

make sure your comp is optimized for using recording software....you need to go into your control panel then go into system settings>advanced>performance>advanced then set your processor scheduling to background services

also you might wanna disconnect from internet...and once you've done that temporarily disable you anti virus software....(seriously, only do that if you've already previously scanned your comp and found nothing on there)

also it helps if you go into your display properties and set your windows and buttons to windows classic style