The exefile field is used to specify a name for the main output file. If you do not supply an extension, LINK assumes a default extension, either .EXE, .COM (when using the /TINY option), .DLL (when using a module-definition file containing a LIBRARY statement), or .QLB (when using the /Q option).
If you do not specify an exefile, LINK gives the main output a default name. This name is the base name of the first file listed in the objfiles field, plus the extension appropriate for the type of executable file being created.
LINK creates the main file in the current directory unless you specify an explicit path with the filename.