Although in this page:
you can read:
How do I back up my configuration and instant message history?
To back up your Skype for Windows configuration and history files, please go to C:\Documents and Settings\your_windows_username\Application Data\Skype\ or on Win7/Vista C:\Users\your_windows_username\ ...
in my C:\Documents and Settings\your_windows_username\Application Data\
directory there is not a Skype subdirectory.
Where, then, are skype instant messages stored? I can read this history for everyone of my contacts.
My skype version is 188.8.131.52