Help! Lost connection to DNS server

[Opti]

Help!  Not sure what to do.
I lost connection to the DNS server an hour ago and I do not know why.

I'm wondering now if some malware got on my system.
Optimum has rebooted my router and modem twice, changing nothing.
Rebooting the PC hasn't changed anything either.
Currently using the emergency WIFI.

Suggestions?
Do I need to take the laptop to BestBuy or somewhere and pay for help?

[grumpyhermit]

Have you tried manually setting your DNS?

www.hellotech.com/guide/for/how-to-change-dns-server-windows-mac

You can try testing with the Google DNS

Google Public DNS IP addresses

The Google Public DNS IP addresses (IPv4) are as follows:

8.8.8.8
8.8.4.4

The Google Public DNS IPv6 addresses are as follows:

2001:4860:4860::8888
2001:4860:4860::8844

You can use either address as your primary or secondary DNS server.

[Opti]

Thanks I did try that, but the issue might be hardware. One rep finally told me about a recessed reset button, which seemed to work after a time. I wonder if the hardware might be failing. 

[bean29]

My Mom is having issues with her router too. I pressed the reset button and nothing, but unplugging the unit in back and plugging back in seems to do the trick.

I also wondered if she needs to replace the unit.

[Opti]

I ended up pulling the plug on it, in order to get it to work. The reset button by itself wasn't enough.