You only have an Express edition of Visual Studio installed. Express editions are not supported. ReSharper does support VS2005, VS2008, VS2010 and VS2012 Standard and above (like, Professional, Ultimate, etc.).
The installer checks certain Registry values when looking for installed Visual Studios. Visual Studio might get corrupted and become undetectable by the installer.
If you have supported Visual Studio editions installed, run "Control Panel | Add/Remove Programs | <Visual Studio> | Repair" action to restore its Registry entries.