onboard nic not detected in windows

I am have pretty much the same problem, NIC is basically unusable while the wireless seems to work fine. Sometimes my Broadcom Gigabit shows up but most of the time it does not. When it does it disappears within 5 or 10 minutes. Since I use the Broadcom at home and the wireless when away they are both needed on a regular basis.

My computer is just over a year old and is under extended warranty so I have submitted a service request. When I get a response I'll try to get back online and let you know what they have to say about it.

Have you re-installed Windows since you first received the machines?  If so, the Chip Set drivers need to be re-installed.  There are also some new drivers out for that NIC.

I haven't had any need to reload Windows but on the chance that the drivers were a problem reloaded them prior to posting the other day. There are 4 different files on the Broadcom 570x driver page and I reloaded 3 of them with no help, the actual driver and 2 others (management and diagnostic).

Also attempted different network configs and cables. Crossover to 1 computer, straight through with a switch to multiple computers as well as changing out the cable itself. Nothing helped in my case.

Contacted tech support and gave them this info as well. They have shipped in a new motherboard since I am on a 3-year on-site warranty. Schedule has their tech doing the job this Friday after I get home from work.