The Daz Studio installer cannot be run from the Daz Install Manager (DIM). The DIM is for Daz content only, which basically means models, figures, materials and so on. To download Daz Studio, you need to click on the ‘My Account’ at the top of this page and then choose “My Downloadable Products”. From there, download and install the correct version of Daz Studio.
There are 64-bit versions and 32-bit versions, as well as separate installers for both on PC and Mac. Be sure to download the correct one before installing.