To be honest I think your laptop cpu and graphics will struggle to play HD files. It may capture them OK as most of the work is done by the PVR box itself.
Your best bet is to download a video file someone has captured (.m2ts/.ts) from their HD PVR and see if it plays on your machine. Just google something like
"hauppauge hd pvr rapidshare" and you will find some samples to download.