Attached Link: http://www.tucows.com/

Poser stuff is usually delivered in one of two formats: DAZ3D uses "exe" installers which install when you double-click on the item. The installers generally aim themselves at the default Poser location, in Program files. The second method of providing Poser files is in zip format. You'd use a zip program to handle them. So I don't know where you got the stuff that uses the RAR format. You can use WinRAR to handle RAR files. One place to get the program is Tucows.