Is there any decompiler out there which can take a .exe file and decompile it into C code (the execution file was also written in C)? Obviously I'm not looking for a 1 to 1 results with the original code, but anything that is somehow readable will be satisfying.
As mentioned above IDA is a great dissembler, but do not expect good C source from the dissembled native object. Overall the range of utilities to manipulate PE executables is quite limited in comparison to more universal and open executable like ELF. I would be more interested in the disassembled assembly since even remotely acceptable C code will not be possible since allot of "user" executables have obfuscated symbols. I haven't used a windows environment in ages, but when I did for disassembly functions I used the Boomerang decompiler which is open source and free http://boomerang.sourceforge.net/