I have tested this on a fresh install of Windows Server 2003 R2 Enterprise x64 Edition with SP2. When installing QuickOPC 5.32, I am presented with a "Blocking Issues" page, which identifies two missing prerequisites: Adobe Reader, and .NET Framework 3.5 SP1. If I ignore this page and proceed, I get the error in the first picture you attached; I have not proceeded further.
If I install the .NET Framework 3.51 SP1 as instructed, the installation proceeds normally.
The fact that the "Blocking Issues" isn't really blocking the user from proceeding further is by design, to cover situations when at least a limited functionality can be achieved when something is missing, rather than leaving the user with complete inability to proceed further.
Conclusion: Unless I get some new information about this, closing as "not a problem" - works as designed.