I was doing a bit of troubleshooting on the Windoze box last night and discovered MLC requires a fairly new driver for Nvidia cards. I was using 445.75, and it works but seemed to have some stability problems for me. I went back to 418.91 which works well for other projects, but is too old for MLC. Right now the latest certified/recommended driver for Windows is 452.06. I haven't tried it yet.