OpenEdge 10.1B SP3 - Hotfix 07 Installation problem

I have just installed OpenEdge SP3 on out test server (without
problem), but when I go to install Hotfix 07 I can't change the
installation folder.

It defaults to "c:\program files\Progress Software....". I click the
Browse button and select the correct folder "c:\epicor\oe101b" but
clicking OK leave the installation folder unchanged. (I'm logged on as
the Administrator.)

Anyone else come across this?