Do I need all AjaxControlToolkit.resources.dll (in folders ar,cs,de,es,fr...) ?

I have just started working with AJAX, and have installed "ASPAJAXExtSetup.msi". Then I add references to AjaxExtensionsToolbox.dll, System.Web.Extensions.Design.dll and System.Web.Extensions.dll. After that I installed "ASP.NET AJAX Control Toolkit", and added the "AjaxControlToolkit.dll" in the toolbox (Visual studio, add items...). Finally I installed "AjaxControlExtender.vsi".

In my project Bin folder, there is 16 new folders, each of them has a file called
"AjaxControlToolkit.resources.dll". The name of the folders is
ar,cs,de,es,fr,he,hi,it,ja,ko,nl,pt,ru,tr-TR,zh-CHS,zh-CHT.
Why do I need them, it looks like some language files? I dont want to have files in my project that I dont use, can some of them be removed? What about the file called "AjaxControlToolkit.pdb"? Is it possible that the performance can decrease when adding all this .dll's (it seems like my project is running slower after doing this, and my laptop CPU often runs at 100% - causes me to restart the PC)?

What I really need is a explanation so I understand what each .dll is actually doing / what functionality it is providing!!! Thank you :)