I cant read Italian, but I think it's the copy error, you need to; Download ModifyPE and save it into %Systemroot%\system32. Open up command prompt, type modifype.exe C:\uxtheme.dll -c (Replace C:\ with the location of your uxtheme.dll) Then makecab and place it in \i386 Then try it. "open up luna theme on my pc with winxp installed normally or open it from my una folder??? if it's the first one, can i copy all the content of the file and create a new luna.thme one?" If you mean Resources\Luna\Luna.msstyle, no, it's Luna.theme in Resources\