If you're looking to download Vivado 2014.4, I recommend checking the official Xilinx website or contacting their support for the most direct and secure way to obtain the software. Xilinx (now part of AMD) often requires registration to download their tools and software, and they may also have specific instructions or recommendations for installation.

: For LabVIEW FPGA users, NI hosts a dedicated Vivado 2014.4 download page specifically for their hardware integration. Key Installation Details

A free AMD/Xilinx account is required to authenticate the download and manage licenses. Downloads - AMD

Since 2014.4 is not on the main download page, you must use the system.