LAN access but no Internet access. Is OK if I reboot.

[Guest]

I have a small office network with several PC's connected. All work fine on
LAN and Internet access. One of the pc's, during the day, will lose the
ability to access the internet. LAN access is fine, all networked drives can
be accessed, all printers can be accessed from this PC when this happens. I
can ping the router however I can not access it via a browser using its ip
address.
I can ping all other devices and I can ping our remote server outside of
our network. I just can't do anything that is Internet based. Can not
access the email on our remote server. If I reboot the computer all works
fine again. This seems to happen once each day and rebooting fixes it. I
thought this might be a DNS issue however even if I use the absolute IP
address I still cannot access anythign via the internet. Have changed the
router, network card, cables. Have changed the ip address of this computer as
well. Have tried using a wireless card and the same thing happens. Move back
to the wired card and still have the issue.

 

[Hans-Georg Michna]

I have a small office network with several PC's connected. All work fine on
LAN and Internet access. One of the pc's, during the day, will lose the
ability to access the internet. LAN access is fine, all networked drives can
be accessed, all printers can be accessed from this PC when this happens. I
can ping the router however I can not access it via a browser using its ip
address.
I can ping all other devices and I can ping our remote server outside of
our network. I just can't do anything that is Internet based. Can not
access the email on our remote server. If I reboot the computer all works
fine again. This seems to happen once each day and rebooting fixes it. I
thought this might be a DNS issue however even if I use the absolute IP
address I still cannot access anythign via the internet. Have changed the
router, network card, cables. Have changed the ip address of this computer as
well. Have tried using a wireless card and the same thing happens. Move back
to the wired card and still have the issue.

Any third party network related software on that computer?

Hans-Georg

 

[Guest]

None at all. All the pc's are set up identically and only having this
problem on this one. This actually started in October and I have restored
the registry back to the point just before it started. Have ran exhaustive
spyware and virus checkers thinking that it is something related to a virus
or trojan. Also this always happens in the late afternoon between 5 and 7
PM. I have checked the scheduler and there are no task scheduled to run at
this time. Checked the registry for unknown entries in the HKLM RUN entries
and can identify all the entries as legitimate. Have checked the registry
under HKCU RUN and found nothing unusual. Very strange....

 

[Phil M.]

I have a small office network with several PC's connected. All work
fine on LAN and Internet access. One of the pc's, during the day,
will lose the ability to access the internet. LAN access is fine, all
networked drives can be accessed, all printers can be accessed from
this PC when this happens. I can ping the router however I can not
access it via a browser using its ip address.

Check the hosts and lmhosts file. Check for strange Proxy settings in IE.
Maybe try a personal firewall to trace all incomming and outgoing activity.

 

[Hans-Georg Michna]

None at all. All the pc's are set up identically and only having this
problem on this one. This actually started in October and I have restored
the registry back to the point just before it started. Have ran exhaustive
spyware and virus checkers thinking that it is something related to a virus
or trojan. Also this always happens in the late afternoon between 5 and 7
PM. I have checked the scheduler and there are no task scheduled to run at
this time. Checked the registry for unknown entries in the HKLM RUN entries
and can identify all the entries as legitimate. Have checked the registry
under HKCU RUN and found nothing unusual. Very strange....

The next step could be to use the Network Problem Solver at
http://winhlp.com/ and follow its advice.

Hans-Georg