internet randomly stops working

ok so ive been having serious internet problems lately. my internet worked fine for months, but ever since ive been back home from school it isnt working properly. most of the time it works fine. but sometimes it randomly shuts off and is very frustrating. sometimes for only a few minutes, sometimes for hours, sometimes for days. i would also like to note that the internet also does not work at the same time on my mothers pc, which is connected directly to the router via ethernet. i can guarantee you that everything is connected properly. ive made sure of this over and over. also, it is not a router issue, as i just went to best buy and purchaced a brand new netgear g600 high speed router. i really dont know what to do. it is connected perfectly, just randomly cuts in and out

here are my router stats
Hardware Version WNDR3400
Firmware Version V1.0.0.38_16.0.48
GUI Language Version V1.0.0.38_2.1.9.1

Internet Port
MAC Address A0:21:B7:80:05:CE
IP Address 98.235.146.194
DHCP DHCPClient
IP Subnet Mask 255.255.248.0
Domain Name Server
68.87.75.198
68.87.64.150

LAN Port
MAC Address A0:21:B7:80:05:CD
IP Address 192.168.1.1
DHCP On
IP Subnet Mask 255.255.255.0

Wireless Port
Wireless Settings (2.4GHz b/g/n)
Name (SSID) blumpkin
Region North America
Channel Auto ( 6(P)+2(S) )
Mode Up to 300 Mbps
Wireless AP On
Broadcast Name On
Wireless isolation Off
Wi-Fi Protected Setup Configured
Wireless Settings (5GHz a/n)
Name (SSID) blumpkin
Region North America
Channel 44(P)+48(S)
Mode Up to 300 Mbps

somebody please help me with this issue, as it is extremely frustrating.
Wireless AP On
Broadcast Name On
Wireless isolation Off
Wi-Fi Protected Setup Configured

also, i have contacted Comcast, my isp, and they came out and checked everything to be fine. my only guess is that there may be an issue with the modem overheating or something of the sort, something comcast didnt notice.

note: internet was functioning properly when comcast came out to check

If you have 2 computers without access simultaneously, one ethernet and one wifi, one windows and one Mac, the issue is either the router or more likely the ISP.

Have you checked the modem when it's out to see if the light for internet connection is working during those times? Have you tried resetting the router during those times?

Does it occur during or just after a rain? If so, I dealt with this issue for almost 2 years with Comcast and got no satisfaction until Time Warner bought them out in our area. A cap back down the line was filling up with water and would knock our service out for 24-48 hours after a rain. And of course, by the time Comcast would send a tech out, it would have dried out and there would be no problem. TW had it fixed the 2nd rain storm we had after they took over. Of course they had to send out 2 techs at different times, 1 typical and 1 real one.

If this is your issue, you're going to be hard pressed to get a response from Comcast to get them out to check the line while the outage is actually occurring. You're going to have to call them every single time it goes out, whether for 10 minutes or a day. They will refuse to come out while you have the problem unless it's been reported three times during in the same month.

Wifi can be affected by the box being physically too close to other electronic/electrical/digital equipment. After several frustrating months of the connection randomly cutting out I turned to my ISP's website which gave me this info. Moved my digital phone base station away from wifi box and internet has worked perfectly ever since. (Made the same reply on a similar thread).