XDE "mfplat.dll is missing" solution

So if you have that problem then your Windows Phone Emulator won't start, and if you try to run it directly you have "mfplat.dll is missing" message, then there is solution that helped me.

Search your %windir%\winsxs directory for "mfplat.dll". It most certanly will find it in something like this, as on my Windows 2008 Standard R2 x64:

c:\Windows\winsxs\amd64_microsoft-windows-mfplat_31bf3856ad364e35_6.1.7600.16385_none_529f8a546d2657c9\mfplat.dll
c:\Windows\winsxs\x86_microsoft-windows-mfplat_31bf3856ad364e35_6.1.7600.16385_none_f680eed0b4c8e693\mfplat.dll

then take 32-bit version of it, and copy it into "%windir%\SysWOW64" ("%windir%\System32" for 32-bit OS).

The other way is probably to install "Desktop experience" feature (on Windows Server OS).

Installing Windows Phone SDK on Windows Server 2008 R2

If you try to install a Windows Phone 7.1 SDK on Windows Server, 2008 R2 x64 in my particular example, I will be surprised that it's officially supported in Windows Vista and Windows 7, as for now.

There is an existing solution for web installer. But what if you internet connection is slow, you need to install SDK on 10 computers, and you have a nice ISO lying on your file server HDD? Actually you only need a good hex editor. HxD is a good one, and absolutely free. What we need, is to modify same lines, but directly in iso file. Open image in editor and search for a unicode string [gencomp7788]. After you found it's location, look down for the same unicode InstallOnLHS=1 and InstallOnWin7Server=1 strings (you can copy baseline.dat from image beforehand and open in notepad for reference, it's located in root directory of the image). Select value 31 after '=' which is '1' and replace it (Edit -> Fill selection...) with 30 which is '0', you will see changes immediately in editor. Now, save the image. You're done. Open the image and verify that changes in baseline.dat are the same as you expected, and you are ready to go!

P. S. I suppose (didn't actually tried that) you can copy files from image into some directory and modify baseline.dat there, but it's not that fun!