@romulovieira-me I am using windows 7 still, and creating [udpsend] works.
I have all the binaries, such as udpsend.dll, in the Pd/extra/mrpeach folder and as the extra folder is searched by default all the MrPeach objects are found by name without any prefixed path.
As the objects are individual binaries the library does not need to be declared.
I suggest you look for where the binaries are located, and set a path to that folder in Pd preferences, or move them into the extra/mrpeach folder.
Then create them by object name without the path prepended.... much less future typing...
David.