Laptop cannot connect to internet

Hello,

I have a Sony VAIO VPCF136FX laptop (running Windows 7 Home Premium 64-bit) that is not able to connect to the internet. I am not sure how this happened... I restarted my computer and I am not able to successfully access the internet. In Device Manager, I have checked all the devices under Network adapters and they all report as working properly. When I try to troubleshoot the problem using Windows Network Diagnostics, Windows lists "The Diagnostics Policy Service is not running" under Problems found. The troubleshooter cannot resolve this. Diagnostic Policy Service is set to startup automatically and to log on as a local service. However, there is nothing listed for it under status and when I try to start it manually I get the following error:

Windows could not start the Diagnostic Policy Service service on Local Computer.
Error 5: Access is denied.

When I have the wireless network adapter in my laptop turned on, it can recognize my wireless network but cannot connect. When I turn the wireless off and use an Ethernet cable, the laptop does not detect any networks

 

Have you messed with any apps like Firewall and/or AV Network security?

 

No, I think it might be a virus that caused it, because the Norton I had expired. I ran a scan with Avast, Malwarebytes, GMER, etc. and found some stuff and removed it. I now have Avast installed so I think the infection is gone, but the damage it caused has not been fixed. I'm almost certain an OS reinstall would fix the internet connection problem, just wondering if there's something else I can do first before trying that.

 

Thanks for the reply. I started up in safe mode with networking, and still couldn't connect, even with Ethernet cable. The laptop is new, and it had internet working on it before, so I still think a reinstall would fix it. What are the stages you mentioned?

 

I will not install Norton on anything. If you let it expire it kills your system. Your best bet is going to be a clean install.