I have this error message when i install QUARTUS II 12.1: Installer subprocess for quartus II web edition exited abnormally status code = 5.

May I know what OS that you were using for this installation?

Check if you are running under admin?

1. Right-click on the .exe and choose "Properties."
2. Then click the "Advanced" button at the bottom of the window that opens.
3. Check "Run as Administrator".

i tried, but the problem not fixed

I have found the solution,

the solution is the internet connection must exist in installation

Good to know on that.