DHCP on students laptops

[Sean]

We've had a couple of laptops from kids on our "Laptops For Students" scheme come back recently that are unable to connect to the network anymore.

I have no idea what they're done to them but they suddenly don't like DHCP anymore - they just say 'Acquiring network address' forever, they don't even time out with the 'limited or no connectivity' yellow triangle message.

Putting them on a static address seems to get them connected but weirdly, even though these are windows XP machines they want to restart everytime you change network settings like win9x used to!

there are no DNS issues that I can see, I have also tried chkdsk, sfc, completely removing network drivers and re-installing them (same thing happen on both wired and wireless connections), removing and re-installing all network protocols and services, running 3 different spyware scanners, doing an over-the-top installation of windows and nothing works!

It's not even the same model of laptop - 1 was a Dell 110L and the other was a Samsung V25

anybody hear of this sort of thing happening anywhere else?

 

Also while I'm here sometimes we get a laptop in that's randomly running slow, we try everything - chkdsk, defrag, spyware scanners etc and the only thing that works is an over-the-top installation of windows - there seems to be no logic to it!

 

Thanks for bearing with me though my rant there!

*breaths out*

[pete]

checked the little darlings haven't blocked dhcp via the built-in firewall?

 

 

re random slowness - you get to a point in windows that the registry has so much cruft in it that a reinstall will make it run noticeably faster. Monolothic config files are a stupid idea.

[NetworkGeezer]

Have you checked that their home ISP broadband CD hasn't installed a lot of gunk. Check the installed protocols and services to see if they any that shouldn't be there.

[Sean]

checked the little darlings haven't blocked dhcp via the built-in firewall?.

 

Had a look and windows firewall is turned off by our own GPOs just fine...

 

re random slowness - you get to a point in windows that the registry has so much cruft in it that a reinstall will make it run noticeably faster. Monolothic config files are a stupid idea.

 

Yeah - could be, are there any programs out there that will remove the 'cruft' without having to do a re-install, or rather of the ones that do are any of them any good?

Doing an over-the-top takes a while by itself but then it also overwrites a lot of the patchs from windows updates...

[Sean]

Have you checked that their home ISP broadband CD hasn't installed a lot of gunk.

 

We do find that stuff is a problem but usualy only with blocking our web proxy settings, not with network connectivity, We uninstalled all the ISP stuff anyway along with and mobile phone syncing stuff but with no effect...

 

Check the installed protocols and services to see if they any that shouldn't be there.

Yeah, I ripped out everything I could which was everything except TCP/IP which greys out the 'uninstall' button, with no effect...

[pete]

don't know about registry cleaners

 

You could keep a drive that's you occasionally slip into a laptop and patch and then just ghost off that.

[Quackers]

Whats the nodetype? (ipconfig /all) ? I found PC's would not get DHCP's when this had some how changed from Hybrid

[ico2]

ipconfig /renew <---- that sometimes works, quite difficult to figure out where the problem is in windows though

[SteveD]

Try rebuilding the IP stack - if it's corrupt or not properly bound the symptoms you describe happen.

 

To do this -

 

Open a command prompt and type the following:

netsh int ip reset [ log_file_name ]

 

e.g. netsh int ip reset c:\log.txt