Bad Starter

[Budd]

Up until about two weeks ago my truck was starting fine....Then the temp dropped to about negative 8. When i goto crank it up, it turns over for about two or three seconds, stops and then makes a ringing noise. ive heard that having bad batteries will kill the alternator and starter, well the alt. died in the summer and i was wondering if my starter is dying also? Also, I plug my block heater in about 7-8 hours before i have to goto work in case anyone was wondering. Thanks for the help.
Budd