To fix this you can try to increase your buffer size in the settings. 1024 samples of buffer size would be enough for most of the mixing/mastering work in real-time.
If you still have problems even though you've set your buffer size to maximum (2048 or more), you might night to upgrade your RAM and CPU. It would be quite hard to upgrade your CPU for a laptop, but you can try to increase your ram to 16GB or 32GB (32GB RAM might be overkill though).