I have Poser 5 & 6 installed (waiting for my Poser 7 physical shipment) so I use nothing but external runtimes.  My Props runtime, right now, is over 40 gigs so externals are definitely the way to go.  If you're using Poser 6 the instructions for adding external runtimes is on pg 69 of the manual or someone will post them again here.

Hugz from Phoenix, USA

Victoria

Remember, sometimes the dragon wins. Correction: MOST times.