you get a

“NSIS-Error!.

with

“Installer integrity check has failed. Common cause include incomplete  download and damaged media.
Contact the installer’s author to obtain a new copy. “

1) Your installer is really corrupted and need to be downloaded again

2) or simply your antivirus / firewall (mostly Norton and AVAST) prevent the full installer to be downloaded correctly,

deactivate the antivirus temporarily and download and install it again.

Posted in: 5 Installation