Want to use WinLatin1 (1252) instead of DOSLatin1 (850, default when cmd.exe is started) ?

You want to apply the new codepage to :
- the current opened command prompt

C:\> chcp 1252

- all the opened command prompt in the future

Start->Run->regedit
Go to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\CodePage]
And change the "OEMCP" value to "1252"

You need to restart your computer to see the changes.

So you'll be able to display extended characters (such as accents and so on)

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Don't know how to check the command prompt's codepage ?

C:\> chcp

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Want to see the result in practice ?
Edit a codepage.txt file and type "à la bonne heure, ça marche ! (peut être)", then open a command prompt and check this out :

C:\> type codepage.txt