If you are a student and if you want to design digital circuits and to learn VHDL/Verilog, then download the Active HDL 7.2 Student Edition. The Size of the file comes around 140MB.
Install as per the recommended settings. Once installed, without license file the application wont open. You need to register to get the license file. The file would be sent to our email Id or directly after registration we can download the file in the web page itself. The license file is applicable only for that machine. If the software has to be installed on another machine, another license you need to download.
Copy the license_student.dat file in the following folder C:\Program Files\Aldec\Active-HDL 7.2SE\Dat. And now the application can be opened and digital circuits can be simulated