You can follow the installation instructions that are available on the download location here:
https://www.harrisgeospatial.com/My-Account/Downloads/mv/vw2/id/7250

When trying to install license wizard my browser give an error code:
DLG_FLAGS_SEC_CERT_CN_INVALID
What Can i do?

The error has to do with trying to connect to our website using a bad address from an older version of our software.

Do you have a license file (license.dat) for ENVI 5.3? If so, you can install it using 'Install a license you have received'.
If you do not have a license, you can go to Company->Contact Us to find the appropriate sales person in your area to inquire about purchasing a license.

I recently dawnload this license. I do not have any license file, is there any solution rather than purchasing.

Hi, I would like to know how to install ENVI 5,3 and how to get the license to use it. I followed installation instruction on the download location on 8th April, but when I tried to open the download page on my account today it said that access is denied.

It appears your account is verified. If you have not been to the website in the last 24 hours, a verification occurs again and this can sometimes take a little while. In this case, please check back in an hour.

I downloaded the license but it said that I don't have any license file. I would like to know how to get the license to use ENVI 5.3?

You would need to purchase a license. Please see the Contact Us page to find the appropriate office or distributor to contact:
https://www.harrisgeospatial.com/Company/Contact-Us