Ok, so I've found tricks, tips and solutions for all sorts of things on these boards before, but now it appears it may be time to ask for help...
Yesterday a laptop turned up in the office that was misbehaving:
Win7 Enterprise says it is connected to our wireless network, but wont map drives or get on the internet.
On further investigation, it has correct IP address from DHCP, but cannot ping servers or the gateway. It resolves the addresses though. (In fact, it can ping two 2008R2 servers, but not most of the others).
If I restart the WLAN AutoConfig service, it starts pinging servers properly, but only for a minute, then stops working again.
If I connect ethernet cable, everything works fine.
I re-imaged the laptop, and it suffers the same problems straight away (other laptops with this same image are working fine).
This morning I got in to discover I now have two teachers, with different manufacturer laptops (and incidentally running win7 Pro rather than Enterprise) that seem to be suffering the same problem.
I knew I'd forget some important piece of information:
Wifi is WPA2-PSK (Its a Meru infrastructure).
The original laptop in question is a samsung, imaged with a vanilla Win7 Ent SP1 image, with only a few drivers added (and office etc) No Wifi utilities or anything, just Windows managing the connection. And I have loads mroe of the same model laptop, with the same image that (at the moment...) are working fine.
The teacher laptops that are now suffering the same fate are Compaqs with Win7 Pro SP1, but have all the HP/Compaq carp they came with (They were set up before I started here, and I haven't got round to re-imaging them yet).
If you have WSUS, try searching for newer drivers (whatever your Samsung's using) - most likely an Intel or Realtek. The updated drivers can then be published and deployed using WSUS. Like other updates, it'll only install on machines that require it.
I did something similar (sometime ago) which resolved a glitchy Intel graphics driver (built in Win 7 SP1). This caused screens to randomly go black for no real reason. The updated driver installed by WSUS cured it.
Feel free to contact me directly firstname.lastname@example.org and we'll make sure you get the right support. Sounds client related but we may have seen this before and be able to offer a solution
As well as what Mark has to offer, three things that we encountered this September:
1) BIOS/Firmware updates for the problem laptops. Given that most laptops remain on the old bios, I can only think that flashing them does a low level reset that a simple shutdown does not.
2) Tracert to a device on a different subnet.... look for unexpected IP's in the results. We had a few machines that for some reason started routing traffic through someone's phone (seriously - the phone's dhcp allocated address was appearing in the tracert path) taking the problem phone off the network restore stability for the affected users.
3) Rebooting some sleeping iMacs that remembered their DHCP allocated addresses from before the summer holidays, when they should have either released or renewed them. The leases had expired - DHCP Server had reallocated them to devices on the WLAN, but then the imacs would wake and effectively steal the IP's back. Kind of like a slow trickle arp cache poison attack.
Check for the exact right drivers off the manufacturer site. We had some hps that had this exact same behaviour when using the builtin windows drivers but when replaced with the proper ones it worked fine.
feel free to contact me directly
I anticipate this COULD be a power saving issue on the clients. Feel free to contact me directly and we can help direct you email@example.com
In Windows 7 you need to disable power saving in the power settings AND in the adapter.
We have the experience to help but just contact us and we'll work through it for you