NetworkManager (in Mint 17.2 mate) recognizes wifi, but does not connect. The solution is to disable ipw2100 driver and install a windows-driver using ndisgtk

inxi -N

Network: Card-1: Realtek RTL-8100/8101L/8139 PCI Fast Ethernet Adapter driver: 8139too
Card-2: Intel PRO/Wireless LAN 2100 3B Mini PCI Adapter driver: ipw2100

sudo modprobe -r ipw2100

With windows driver wifi connects (slowly, about in a minute).

There is two drivers who both are working

Driver 1 -> Intel(R)PROWireless21_125836.zip

Driver 2 -> W20mPCI.zip