The driver release notes states that 5.10 doesn't support ConnectX-2.
The last driver version to support ConnectX-2 devices is WinOF 4.80 available under:
Win 8.1:
http://www.mellanox.com/downloads/WinOF/MLNX_VPI_WinOF-4_80_All_win81_x64.exe
Win 7:
http://www.mellanox.com/downloads/WinOF/MLNX_VPI_WinOF-4_80_All_win7_x64.exe
Please note there's no compatible ConnectX-2 driver for Win 10.
Manuals:
http://www.mellanox.com/related-docs/prod_software/MLNX_VPI_WinOF_User_Manual_v4.80.pdf
http://www.mellanox.com/related-docs/prod_software/MLNX_VPI_WinOF_Release_Notes_Rev_4.80.pdf
http://www.mellanox.com/related-docs/prod_software/Mellanox_Windows_Network_Adapter_Management.pdf