Hrm...I don't remember getting any PMs about setting up Mednafen but I can give you the basics for getting CDs to run under it.
First of all, you need to either know what parameters to pass to Mednafen, or else just be able to edit the config file. Since it makes much more sense to edit the config file, I'll cover that instead.
You'll need to change a few things in mednafen.cfg. Open it with Wordpad or Notepad++ (NOT the original Notepad, it only supports CRLF, and mednafen always does Linux-style linebreaks). Look for these lines and make the following changes and checks:
dfmd5 change this to a 0 (this is right at the top of the config file...if you're using mednafen for MSR testing, this will ensure your saves are not hosed when new patches become available)
pce.cdbios you need to set this to an actual CD bios image. Mine is syscard3.pce, so that's what gets written. For ease of use, copy the system bios to the mednafen directory and just use the filename so you don't have to screw with paths. Also, mednafen is picky about system BIOSes...I've been unable to get the 256KB US BIOS to work, but the overdumped 384.5K Jp BIOS works fine.
pce.forcesgx if this is set for 1, set it for 0. It sometimes causes alignment problems when using the emulator as a PCE.
pce.nospritelimit make sure this is set for 0 ALWAYS. Some games (MSR included) rely on exploiting sprite buffer overflow.
After these are set, you can load the cuesheet DIRECTLY through mednafen...you don't need to mount it with Daemon Tools. It's a snap too...as long as you know at least a LITTLE of how to work the commandline!
Make sure your mednafen directory is somewhere easily accessible. I put mine in C:\mednafen for ease of use. So, to get to it, it's a simple two-part operation:
c:
cd \mednafenfrom the commandline. Now, you can load the cuesheet easily. I have MSR stored at E:\msong and the cuesheet is called __msr.cue so it looks a bit like this to start it up:
mednafen E:\msong\__msr.cueIf everything is set up correctly, mednafen will come up with the system BIOS loaded so you can run the disc image. Of course, you might want to configure the controls as well. For the version I use, you press and hold Alt and Shift, and while still holding them, press the 1 key. This will bring up the control config function. Just follow the onscreen directions to set up your controls, it's very very brainless. It will ask you for each one twice, so hit the key you want twice for each (I have mine set up to use my PS2 gamepad, hehe).
Maybe someday I'll write a visual frontend for mednafen. Or maybe not...hehe

Kitsunexus:
Mednafen is a multiple console emulator that is renowned for its accuracy. Right now, it's the only emulator known to properly emulate the PCE, SGX, and PC-FX in one shot. It also emulates the NES, the Lynx, the Wonderswan, the Gameboy and Gameboy Advanced, and the Neo Geo Pocket.