Hi tonylfc,
Can I ask if you have already run DAZ Studio 4 a couple of times and registered it?
On most versions of Daz the needed library files only become available after its been run and registered, so if yours is a new or recent install that might be the problem.
Once Daz has been registered the default location for the libray file is here -
"C:\Users\*your*user*name*here*\MyDocuments\Daz 3D\Studio\My Library"
The Evolution morph installer is looking for that location because the morphs need to be installed into the same folder as the Genesis figure, which can be found in the 'My Library' folder.
So if that doesnt work, then let us know which version of Daz you are using (3.5, 4, 4.6 - etc.) and also what operating system (windows 7, 8 or XP) you are using?
It matters because on different systems Daz will put the needed folders in different locations.
Hope that helps and please let us know how you get on with the instalation.
Cheers, Maf