1.Just right click on setup.exe of SONAR n click on the "properties" at the bottom of menu bar.
2.In properties page hit compatibility tab and select tick on "Run this program in comparability mode for:"
3.Select windows 7 or windows 8 (what ever version of windows u have) in compatibility mode.
4.Also select tick on "Run this program as an administrator" and click Apply then hit OK.
5. Now run again SONAR setup.exe, it should work.