Hello John,
Many thanks for the interest in Hauptwerk.
[Topic moved here, since you're currently using the Free Edition.]
If feasible (if your laptop will support it), I'd suggest upgrading to Windows 8.1 64-bit, doing a clean install of Windows (re-format) in the process, since in my experience Windows 8.1 is generally better for audio reliability than Vista. (Also we don't now officially support Vista, although I'd expect it still to work as before.) Simply doing a clean install of Windows (re-formatting) often improves Windows performance drastically.
The quality of the audio interface and its drivers is also extremely important for reliable low-latency audio.
Apart from that, I'd suggest working through the Windows performance troubleshooting suggestions in the user guide (pages 214-216 in the current v4.1.1 version).