Windows 7 connects to router but keeps dropping connection to Internet.

I was asked this by a "friend" online and had no ideas, so thought I would ask you here.
here is the situation

Asus laptop running Windows 7 and it keeps dropping it's internet connection. It connects for a minute or two then drops the connection, but stays connected to the router.
The computer connected driectly to the router via ethernet cable works fine, and another laptop connecting wirelessly does too, so the problem has to be with that computer somewhere.
And they hae tried the following:

- Rebooted laptop & modem
Booted into Safe Mode with Networking
Did a clean boot
Uninstall and reinstall Wireless NIC
Deleted drivers and reinstalled brand new up to date drivers
Did system restore to before the problem started
Reset Windows Firewall to "proper settings for your computer"
Disabled Windows firewall
Disabled Comodo firewall
Ran full Malwarebytes scan & removed three objects
Ran Comodo AV quick scan of system type files
Set TCP/IP 4 to static IP, Gateway, & DNS severs
Deleted the network connection & recreated it

None of the above made any difference, My inclination is that the NIC is pooched, anybody got any other ideas of things to try?

 

It's the router that establishes and maintains the internet connection, not any attached computer, so have you examined its status lights? If the internet light is permanently green there could be a missing or faulty filter in the house somewhere, not necessarily the one the router is attached to, or the house internal phone extension wiring may have a fault. If the internet light is intermittently going amber, and you have ruled out any of the above problems, then it's the phone line itself or your ISP's kit at the exchange. You need to be absolutely certain it isn't an internal issue before calling out the line provider or your ISP. Here in the UK that can prove rather expensive!

I'm assuming here that this is a phone line connection rather than satellite or cable of course.

 

btw, how did you establish that this computer remains connected to the router when the internet drops out? If that's right it rules out the NIC of course.