(Sorry, I can't follow your session log because there are too many things going on in it at once. It's too dense and complicated.)

Sorry, let me simplify it.

This is in a completely new session as identified by the banner at the top. Everything you see in the session was typed manually, not copy&pasted. (This is important!). As I stated above, I am typing the 'ó' using AltGr-o:

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

c:\>dir ac*/b
File Not Found

c:\>chcp 65001
Active code page: 65001

c:\>echo this is the contents of acentó.dat >acentó.dat

c:\>dir ac*/b
acentó.dat

c:\>perl -pe1 acentó.dat
this is the contents of acentó.dat


c:\>
[download]

The reason typing rather than cutting and pasting is important, is because the character code that sits behind the ó glyph will vary from codepage to code page.

Hence, note the glyph displayed when the contents of a file created under cp437 are displayed under cp65001. On screen, prior to cutting and pasting to perlmonks, that � character is displayed as the typical 'open box' glyph.

c:\>chcp 437
Active code page: 437

c:\>echo this is the contents of acentó.dat > acentó.dat

c:\>dir /b ac*
acentó.dat

c:\>perl -pe1 acentó.dat
this is the contents of acentó.dat

c:\>chcp 65001
Active code page: 65001

c:\>dir /b ac*
acentó.dat

c:\>perl -pe1 acentó.dat
this is the contents of acent�.dat
[download]

So, your inclusion of the codepages confuses rather than clarifies.