I just encountered the same behavior. Steps to reproduce:

* Install Python 3 (I used 3.9.5) on Windows
* Use the Admin console to create a python3.exe link, e.g.

    cd "c:/Users/niklas/AppData/Local/Programs/Python/Python39"
    mklink python3.exe python.exe

* Use python3.exe to create a venv, e.g.

    python3 -m venv

The environment is created up until the point _setup_pip() is called in venv, which causes the following error to be printed:

    Error: [WinError 2] The system cannot find the file specified

Running venv from the interpreter gives the full stack trace.

    $ python3 -c 'import venv; venv.main([".venv"])'
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\venv\__init__.py", line 491, in main
        builder.create(d)
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\venv\__init__.py", line 75, in create
        self._setup_pip(context)
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\venv\__init__.py", line 299, in _setup_pip
        subprocess.check_output(cmd, stderr=subprocess.STDOUT)
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\subprocess.py", line 424, in check_output
        return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\subprocess.py", line 505, in run
        with Popen(*popenargs, **kwargs) as process:
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\subprocess.py", line 951, in __init__
        self._execute_child(args, executable, preexec_fn, close_fds,
      File "C:\Users\niklas\AppData\Local\Programs\Python\Python39\lib\subprocess.py", line 1420, in _execute_child
        hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
    FileNotFoundError: [WinError 2] The system cannot find the file specified