Not sure what you mean by "it wont let me", but if you are seeing the message about the install file being corrupted please see the info below:
As of late January, Microsoft Edge on Windows 10 (formerly known as Internet Explorer), and Internet Explorer on Windows 8.1 seem to have an issue with some of PreSonus's software downloads on Windows. An issue has been logged with Microsoft.
To resolve this you can change settings in your browser:
See the second post / response from Microsoft in this Answerbase article:
http://answers.microsoft.com/en-us/windows/forum/windows_10-networking/the-signature-of-this-program-is-corrupted-or/6e1d5659-6bb4-4e1f-941e-27093192d80b?auth=1
As an alternate option you can use a program like FireFox to download the software.
https://www.mozilla.org/