how to install firefox 12-51/52 esr in order to browse mydlink portal

Since you are using Windows a easy way is to perhaps use the portable Firefox 52.9.0esr as you can run it in its own folder on your SSD or hard drive or even off a usb flash drive. Portable Firefox has been around since the early days of this browser and It is self contained so it will not touch your Profile(s) used in your normal Firefox install as it uses the official Firefox builds (with permission from Mozilla) with a custom launcher FirefoxPortableLegacy52_52.9.0_English.paf.exe https://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox,%20P.E.%20Legacy/Mozilla%20Firefox,%20Portable%20Edition%20Legacy52%2052.9.0/