Solution: Replace the corrupt machine.config file with the default one
In almost all cases, Windows starts spewing out parsing error 0xC00CE556 when it tries to parse the machine.config file in the directory “C:\\Windows\Microsoft.Net\Framework\v2.0.50727\Config\” but fails because machine.config is corrupt. Since that is the case, simply replacing the corrupt machine.config file with a fresh, default one should get rid of the problem.
Hold the Windows Key and Press R. In the run dialog; type
C:\Windows\Microsoft.Net\Framework\v2.0.50727\Config\
OR
%windir%\Microsoft.NET\Framework\v2.0.50727\CONFIG\
Look for a file named machine.config.default. Move/Copy machine.config.default to a new location – the Desktop, for example.
Back in the C:\\Windows\Microsoft.Net\Framework\v2.0.50727\Config\ directory, delete the corrupt machine.config file.
Go back to the machine.config.default file, and rename it to machine.config. If asked by your computer whether or not you really want to mess with the file extension, confirm the action.
Move the new machine.config file to C:\\Windows\Microsoft.Net\Framework\v2.0.50727\Config\.
Close File Explorer and restart your computer.
Once your computer boots up, you should no longer receive parsing error 0xC00CE556.