my zte mf667 modem isnt installing. i have updated to os x yesomite 10.10.2

Please try to provide at least your Country of residence in profile. Most Modem devices are associated with an ISP. It appears to me that, you are from India, in that case, you can follow this guide - https://thecustomizewindows.com/2014/11/reliance-3g-usb-modem-os-x-yosemite/

This is written for Reliance as ISP. However, the basic method will be the same for any service provider.

The ISP packages a software which is not upgraded. That does not with Yosemite. You need to run the daemon and configure manually. I have not seen any universal Free Software application which works with most of these devices, in that case any of us could modify the App.

If you can not configure yourself, you can take the help of Apple shop by visiting physically. Apple unfortunately possibly never received the updates from the brands. Why I have no idea. In short, we have to code a free software ourselves.