Thanks to Anthony, Vincent, and most of all PaulR, I now have portal v5 running quite happily on a vmware partition.

Moral of the tale ? Portal should install quite happily - if it doesnt, suspect the install kit (mine was slighly corrupted during unpacking). Good advice from Vincent - DONT have any spaces in the pathnames of the target installation OR of the source portal install kit, and keep the source portal install kit pathname SHORT.. (on wintel especially..).

Did over 1,000 miles of driving between friday and this evening - Leuwaarden, Amsterdam, Edinbugh, Perth, Dunvegan, Noranside, and home. Knackered. Still, some bike-inspired fun for tomorrow..