Why do I get a black screen when I connect to my Windows server via RDP (Remote Desktop)?

This issue is a known Windows bug that occurs when the primary drive ( C: ) runs out of available free space. When this happens, Windows often overwrites control panel color settings for the desktop and login screen, resulting in the “blacked out” login screen and/or desktop.

When the login screen is black, you can often still access the normal Windows desktop, you just have to alt/tab through the various login screens:

When you first connect via RDP, there are two blanks you can tab through, the top one being the username (which should be Administrator,or, whatever you have set as your admin name), then, when you tab again, you will be in the password field. After entering the username and password, you should be able to Tab/Enter, and gain access to the system. If the system was just recently rebooted without warning, another screen (black) will pop up, asking why the server was rebooted. You can type anything here, and tab/enter again.