Spyder (with Anaconda): An error occured while starting the kernel - python-3.x

Question

I just installed Anaconda, but when I start Spyder it displays "An error occured while starting the kernel".
I tried updating everything, and unistalling/reinstalling Anaconda (inspired by what I have seen on other posts), but it doesn't work.
(It doesn't work either if I use the Jupiter or other programs).
Here is the full error message:
Traceback (most recent call last):
File "C:\Users\Quentin\Anaconda3\lib\runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "C:\Users\Quentin\Anaconda3\lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\spyder_kernels\console\__main__.py", line 11, in
start.main()
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\spyder_kernels\console\start.py", line 306, in main
kernel.initialize()
File "", line 2, in initialize
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\traitlets\config\application.py", line 87, in catch_config_error
return method(app, *args, **kwargs)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\ipykernel\kernelapp.py", line 562, in initialize
self.init_kernel()
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\ipykernel\kernelapp.py", line 447, in init_kernel
user_ns=self.user_ns,
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\traitlets\config\configurable.py", line 412, in instance
inst = cls(*args, **kwargs)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\spyder_kernels\console\kernel.py", line 37, in __init__
super(SpyderKernel, self).__init__(*args, **kwargs)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\ipykernel\ipkernel.py", line 68, in __init__
kernel = self,
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\traitlets\config\configurable.py", line 412, in instance
inst = cls(*args, **kwargs)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\IPython\core\interactiveshell.py", line 687, in __init__
self.init_magics()
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\ipykernel\zmqshell.py", line 593, in init_magics
super(ZMQInteractiveShell, self).init_magics()
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\IPython\core\interactiveshell.py", line 2250, in init_magics
m.PylabMagics, m.ScriptMagics,
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\IPython\core\magic.py", line 405, in register
m = m(shell=self.shell)
File "C:\Users\Quentin\Anaconda3\lib\site‑packages\IPython\core\magics\osm.py", line 52, in __init__
self.execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
File "C:\Users\Quentin\Anaconda3\lib\re.py", line 234, in compile
return _compile(pattern, flags)
File "C:\Users\Quentin\Anaconda3\lib\re.py", line 286, in _compile
p = sre_compile.compile(pattern, flags)
File "C:\Users\Quentin\Anaconda3\lib\sre_compile.py", line 764, in compile
p = sre_parse.parse(p, flags)
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 924, in parse
p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, 0)
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 420, in _parse_sub
not nested and not items))
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 810, in _parse
p = _parse_sub(source, state, sub_verbose, nested + 1)
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 420, in _parse_sub
not nested and not items))
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 501, in _parse
code = _escape(source, this, state)
File "C:\Users\Quentin\Anaconda3\lib\sre_parse.py", line 402, in _escape
raise source.error("bad escape %s" % escape, len(escape))
re.error: bad escape \M at position 52
I would be very grateful if someone would help me.

Answer 1

So I met someone who was good at this and he solved my problem.
He somehow figured out that there was a problem with my environnement variables.
In the environnement variables, in the system variable PATHEXT, are stored some extensions (.COM, .EXE, .CMD,...) that can be recognized by the system. I had an alien in mine, which was not an extension (in that case, it was "C:/HOME/MinGW").
I deleted it and it worked.
This can be set via Window's configuration pannel -> modify system environnement variable. Then press on "environnement variables". On the "system variable" list, select "PATHEXT" and press "modify...".
(NB: My Windows is in French so the names are translated by myself and may not perfectly match to other languages'Windows)