I just bought a new laptop with Windowns 8.1 build 9600. When I reviewed all the posts on the port being grayed out (which I have on 1.6.3), nothing works for me. They said download the latest nightly build. So I did and when I try to load it, I get the message I need to install "atleast" Java Developer Kit 1.8. So I download Java Developer Kit 8 (the latest) and try to install the Arduino IDE and I still get the same error message I need to have installed Java Developer Kit 1.8. This is very frustrating. I just want to start developing Arduino projects and I can't even get started. I really don't know what to do.
The JVM is included with the IDE. You don't need to install anything. 2 days ago we released 1.6.4 which contains a fix to the greyed out port menu. Please give it a try http://www.arduino.cc/en/Main/Software
Thanks. Sorry, what I forgot to mention is that I was trying to connect to the RedBoard from Sparkfun which uses the pesky FTDI232x USB UART. I bought their Inventers Kit and was dying to get started. I finally found a thread that had me go to the manufacturers web site and download the installer. Finally got it working. Had to go to the Advanced Startup Options to turn off the USB signature cert checker and ran the installer as Administrator. WHEW. But it worked. Thanks again. --Ron