I had a number of installation/upgrade tries fail recently with this generic code 1603 error on SW 2010, 2012 and 2013. On completing the installation SolidWorks did not function correctly with lag times on rotate, pan, keyboard etc or did not install at all. The only way I got these installations to work was to uninstall all versions, clean the Windows registry, and do installations from setup.exe in the swwi/data folder, NOT the Installation Manager. This is on a Win 7 x64 system. SolidWorks always says use the Installation Manager to make sure you get the correct updates. Just the opposite for me. With a full DVD equivalent download from the Customer Portal for the current service pack of each release, only setup.exe worked without problems. In fact, on one attempt to upgrade SW 2012 from sp4 to sp5, which failed, it screwed up my SW 2013 sp1 installation so it wouldn't start with a Visual Basic failed to load error. That's when I started over. Three days of frustration to finally get properly working versions of the releases I needed.
I'm seeing something like this on 2012 SP5.0EV.
What did the installation logs (hyperlink in the message dialog) say?