Metal Gear Solid is a PS1 game, (In other words) it won't work if you burn it to a DVD. With free mcboot you have only three choices as of this date:
1. Use PS2PSXe - A ps1 emulator for the ps2. I've personally tested this game on the emulator and it's not very comfortable to play (frame rate is up and down, sound errors etc.).
2. The POPS-00001 emulator that was recently leaked (only works if you have an internal HDD). I've read reports of that particular game not running too well on this emulator either, but I haven't tested it personally.
3. Swap Method - This would involve burning each disk to a CD and using either the uLaunchELF or psxlauncher app (stops the original disk from spinning, making it safe to swap) to swap an original ps1 game with your burned MGS CDs. Do some more research and figure out how it works. This is the only option I've mentioned so far that may guarantee 100% playability.
Don't get me wrong;...
I love the weirdos...
I just hate the freaks