I have tried nurmous drivers and disabling bonjour and i am still having my internet cut out non stop. i cant even run a speed test without it failing on me.i have read nurmous other people have this issue as anyone figured this out yet? im at a loss as what to do.
Hello and welcome to the forums.
TorrentG's suggestion of uninstalling the AVG firewall product is a good and sound way to move the diagnostic process steps along and it costs nothing but a few minutes of your time. You can always promptly reinstall it later once you've managed to resolve your current issue. As TG suggested, Microsoft Security Essentials has been found to be a satisfactory substitute for most of the top tier AntiVirus / AntiMalware products so it might be worth your efforts http://www.microsoft.com/security_essentials/
Although, I haven't seen the autonegotiate issue with some Gigabit Lan Cards happen intermittently (usually it either works or it doesn't) you may try this and see if it works for you.
type ncpa.cpl into the search box and hit enter
on the network connections page select then right click your adapter and choose properties
on the local area connection properties dialog box click the Configure button near the top
on the resultant dialog box choose the advanced tab at the top
in the left box/frame labeled Property: look for something called Speed & Duplex, select it
and then use the drop down arrow under "Value" to select 100 half
OK your way back out of there, reboot your computer
Let us know if that helps at all.