Hi I'm new here, I got mine working with Vista and all i did was right click the app. Then click Properties. Then go to the compatability tab. Then tick the box Run this game in compatability mode for: and then choose Windows 98/ Windows ME and then after that tick the box Run this program as an administrator and it worked. If it still doesnt what i did was with a shortcut on the desktop i added "-w" on the end of the long thingy like this
"C:\Program Files (x86)\Metal Gear Solid\MGSI.exe" -w
That puts it in windowed mode.
Then if that works, go to the menu and then options and advanced and make sure one of the things says Software, if it is Hardware then change it. To run it full just quit the game and remove the "-w" off the end and it should work in full screen. If it crashes in fullscreen then just add the "-w" back on. It looks terrible in windowed mode
Let me know if it works for you