OK This gonna be easy to fix!
So what you need to do its go to "Documents" that you can find in "Libraies" in "Windows Explorer/Floder"
Now to toEA Gamers And now goto "Medal of Honor" And now to "Multiplayer"
Now open "Settings" ( if u cant open it click MOUSE2 (Right bottom( And then go to "Open with
Notepad) And now change the "DxVersion=Auto" to "DxVersion=9"

To fix it u have 2 options
One (reccomanded)
Go to Local disk>Windows>(If you have 32 bit go to System32 and if you have 64 bit go to SysWOW64)
Now scroll down and find PnkBstrA
Click on the right bottom (in your mouse)MOUSE2) And the go to Properties
Now click on the Compatibility Tab
Now look down and click on Change settings for all user
Now look down and check the Run this program as an administrator
Now do ok And lunch Medal Of Honor and enjoy! :D
(if it will not work try to lunch first singleplayer)
Option 2 (Not reccomanded
Uninstall PunkBuster
Reinstall it
Add the game Medal of Honor
And then wait
Ok when you finish it Lunch first Single player and then play Multiplayer
(Yeap i dont rly sure dat its work but if option 1 dont work so do this option too)