No way. First of all, *.EXE is nothing but a pattern for a file name, it is used by the Shell but internally means nothing; the actual use of the file is defined by its internal structure, often a signature, which is "MZ" in this case, "ZM" is also allowed. This is the Portable Executable file, which also includes DLLs and a lot more. Please see:
https://en.wikipedia.org/wiki/Portable_Executable[
^].
.NET files is only a subset of PE files. Please see the section of the same article,
https://en.wikipedia.org/wiki/Portable_Executable#.NET.2C_metadata.2C_and_the_PE_format[
^].
Interestingly, on non-Microsoft systems, CLI PE files (.NET executable files) can be used, without recompilation, as CLR executable files, under Mono. In such systems, *.EXE and *.DLL really indicate CLI files. However, this is not a strict rule, because, as I already said, the file name pattern does not matter much, especially in *NIX OS, where so called historical concept of "file name extension" never existed, in contrast to Windows, where it came from obsolete file systems.
See also:
http://en.wikipedia.org/wiki/Common_Language_Runtime[
^],
https://en.wikipedia.org/wiki/Common_Intermediate_Language[
^],
https://en.wikipedia.org/wiki/Mono_%28software%29[
^],
http://www.mono-project.com/[
^].
—SA