Arris TG862g Replacement

I've been having problems with the signal to my laptop dropping out. I contacted Comcast Xfinity and they told me I should update the router. I'm not a techie and my wife and I are retired . I guess I'll go to Best Buy and get something to replace this one, but before I do I wanted to make sure its the modem and not something I could"ve overlooked and fixed. Thanks for any help.. Arris TG862G..