That code won't even compile: Process.Start takes a string, not a (to C#) odd sequence of characters.
Try:
Process.Start(@"C:\Users\Administrator\Desktop\file.exe");
Your error may be coming from a different version of your code given that this version will not compile.
Error 0xc0000142 is "the application failed to start" and may be related to application word size: if your app is 32 bit you may have problems starting a 64 bit app, and vice versa.