MaryB,
We have lots of users running a wide variety of versions of our products, so it's difficult to cover them all here.
It really depends on what your current version of GEOPAK and MicroStation is. You can only run one version of MicroStation on a machine and GEOPAK Suite needs MicroStation 397. So, one option is to install MicroStation 397 and run both GEOPAK Suite SELECT series 2 and SELECT series 3. Another option is to run your current MicroStation / GEOPAK Suite as is, and use PowerGEOPAK SELECT series 3. With the Power Products, you doen't install MicroStation, as it's all packaged together. If you are using the beta version of GEOPAK, which was PowerGEOPAK, then you must uninstall prior to install the released version of PowerGEOPAK.
Lou