Here are all important links:
http://lmms.io/forum/viewtopic.php?f=1&t=4740
-A few rules and useful forum instructions
If you like to introduce yourself, to the community, go here:
http://lmms.io/forum/viewtopic.php?f=4&t=4480
The reason is the settings for security in windows 10.
Windows like to prevent software that is not approved by Microsoft, to be installed.
They take a serious fee for that 'signing-with-microsoft'. That is something lmms cant afford!
But you can around it!
First you must be logged in as Administrator
If you do not have that account, you need help from the Administrator!
As administrator, you then ask for download. You will get a popup, asking if you mean to get software not signed. You then need to scroll complete to the right -Out there out of view, there is a button: "Install anyway" Then you get to install the software, but only from your Admin-account!