The placing of Poser doesn't matter. I have all my poser versions, from Poser 4 and onwards, on the same - external - drive. They coexists happily without interfering with each other.

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.