Dual monitor problem.

I just recently found a CRT in my garage, and I figured I could have dual monitors hooked into my computer. I run a nVIDIA GeForce 6600 GT running on the latest updated drivers. My first CRT is hooked into the VGA port, while my second CRT is hooked into a DVI port using a VGA to DVI adapter. Both monitors look fine when I start my computer, however, when Windows opens my second CRT monitor (hooked into the DVI port) immediately goes to the screen test and then goes blank. How do I fix this problem so I can have both monitors display the same Windows screen?