What is TCDEFexe?

Answer 1

TCDEF.exe probably relates to Borland Turbo C (TC). I can't find any info on the file itself, other than that some people using TC seem to have problems locating the file during compilation. That's usually a sign of a bad install or (more likely) the presence of malware. Given the lack of information I suspect TCDEV.exe is not a legitimate part of TC.