Browser lost internet

Hi,

I have an iMac and suddenly Firefox says there is no internet connection. Same with Safari & Chrome.

When I log into "guest" account on same machine there isn't a problem.

I have deleted & re-installed Firefox to no avail. Other items on my main account eg Google notifier & radio work as normal.

I'm flummoxed. Any ideas please?

G'day and welcome to the forums.

When in Admin Account set up the modem/router again using the manual and URL. Also helps if you provide computer and operating system detaius.

Hardware Overview:

Model Name: iMac
Model Identifier: iMac11,3
Processor Name: Intel Core i5
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 4
L2 Cache (per core): 256 KB
L3 Cache: 8 MB
Memory: 8 GB
Processor Interconnect Speed: 4.8 GT/s
Boot ROM Version: IM112.0057.B00
SMC Version (system): 1.59f2
Serial Number (system): W804039DDB5
Hardware UUID: 88B53AE7-3AE7-59D4-B782-F3A3C275D09D

G'Day Harry,

I don't understand "modem/router again using the manual and URL"
The router is working fine but all three browsers refuse to recognize it on main account whilst it all works on guest account.

Obviously there is something wrong with the Network setup up under the admin account. Is why suggested deleting all in System Preferences and starting again. Is the Location set as "Automatic"?

Harry,

It's set to automatic.
I've just compared the network settings to both the admin acct & the other acct that works.
They are identical & looking at the settings pane I'm doubtful that I know what I'm doing.

Will have to research. Weird having to read docs on one acct & change to admin to work on them.

Thanks for trying,

Peter

It might be worth going through this document and trying a few of the things listed.

Thanks Vansmith,

Looking at document now, interesting. I'll give it a read.

Thanks

I recommend you try a safe boot:
OS X Mountain Lion: Start up in safe mode

It "may" fix your issue, but even more importantly, it gives us a known starting point.

Have you tried using generic DNS addresses such as Google's 0.0.0.0?

0.0.0.0 is the address for non-routable requests. Google's DNS addresses can be found here.

Did a safe boot. No firefox visible. Went back to normal mode & I downloaded firefox on working account. Copied to external drive & installed it on non working account.

Now whenever I try to open firefox it crashes instantly.

Thank you Australia & Canada. In London it's half past midnight so going to bed.