Saturday, March 28, 2009

Can't get on the internet (broadband)!

Probably the single most common problem I'm asked to resolve is the user who can't get on broadband internet ("my broadband isn't working!").

Here I'm going to attempt to explain the basic diagnostic steps I'd take to find out what's going wrong. Do this yourself and you could save yourself the cost of calling me out! But first - most importantly -if you're having problems getting on the internet then you won't be able to read this so be prepared and print it out and tuck it away somewhere safe!

There's a lot of text in this article so get yourself a nice cuppa and settle down... alternatively, just print it out and file it away until you need it. Of course, by then it'll be too late to ask about anything you didn't understand!




Before we get going it's probably worth while saying that many problems are fixed by simply rebooting the router (not the main computer!), i.e. turn off the power, wait 5 seconds and then turn it on again. It'll spend a couple of minutes with its lights flashing but eventually will settle down and you might just find the problem has gone away!




Let's start by establishing what environment I'm talking about - and note that the processes I'm describing refer to Windows XP or Windows 7. It's very similar on Vista but it's up to you to find out what Microsoft have decided to call the various things in order to find them!

I'm talking of a computer which connects to the internet using a router and also that it uses the normal networking setup.

This doesn't apply if you're using a broadband modem (common ones are Thompson Speedtouch, Sagem modem and BT Voyager 100 or 105). These are small boxes connected to your computer using a USB cable).

As for 'normal network setup', if you've changed the setting you'll probably know about it. What I'm describing isn't necessarily going to be totally correct if you've set a static IP address. If you don't know what I'm talking about, don't worry - it means you probably haven't!

Step 1 - OK, so first thing, is your computer talking to the router?

To test this go to the Start button and select "Run...". This will bring up a box in which you can type a command so type in 'cmd' (without the quotes) and press enter. Now you'll get a bigger command window. In here type 'ipconfig' and press enter...

You should be presented with something like

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 192.168.0.2
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1

There may be several such entries and it may mention 'wireless' in there somewhere (and Vista will look even more complicated!). What this is telling you (if it worked) is that your computer has an IP Address (think of it as a telephone number) of 192.168.0.2 and your ROUTER has an address of 192.168.0.1.

If that's showing OK, then it's a good start - your computer looks like it is talking to the router but we'll just confirm that so type in
ping 192.168.0.1 [but replace this number with the default gatway address above] and press enter

now you should get something like

Pinging 192.168.0.1 with 32 bytes of data:

Reply from
192.168.0.1: bytes=32 time=2ms TTL=245
Reply from
192.168.0.1: bytes=32 time=1ms TTL=245
Reply from
192.168.0.1: bytes=32 time=2ms TTL=245
Reply from
192.168.0.1: bytes=32 time=2ms TTL=245

Assuming that you do get this then the computer and the router are indeed talking to one another and so you can move to Step 2!

Still here then? So you didn't get that stuff se we need to know why it's not talking to the router. Possible causes are (including the really simple stuff)...

  • Your computer's network card isn't turned on
  • Your computer's network card isn't working
  • The cable between computer and router is unplugged
  • The cable between computer and router is defective
  • The router isn't turned on (sort this one out yourself!)
  • The router isn't working
  • There's something wrong with the wireless link
Until now I've not mentioned wireless connections and they, of course, introduce a whole new set of problems so if you're not connecting to the router at this stage, try it without the wireless and connect the computer directly to the router with an ethernet cable (one probably arrived with your router) then see if the broadband is working and if not, go back and repeat step 1.

If it is then go down to the later section about Wireless Problems.

So let's look at the possible problems but first have a look at the router. There should be a light on saying something like 'LAN' which, if you unplug the ethernet cable, would go out. If this light isn't on then one of the following may be the cause...

Network card not turned on? To check this, go to the Start button and select control panel and double click on 'Network Connections'. You should see someting like "Local Area Connection ..... Connected". If it says "Disabled" then right click on it and select "Enable" then go back to step 1.

Network card isn't working? It could be a simple case that the hardware's failed!

The cable between computer and router is unplugged? If you need me to help you sort this problem then maybe you should try a little gardening instead!

The cable between computer and router is defective? Try and get hold on another cable to try. It could have become defective.

If the LAN light IS on then there seems to be a problem with the router and it's now getting very tricky to sort this out yourself! It could be the configuration of the router (DHCP settings and other such technical terms!) or simply that the router has stopped working.

Step 2 - Is the router talking to the internet?

In the command window (which you've still got open) type the following...
ping 173.194.37.104
and press enter

Hopefully you should see something like

Pinging
173.194.37.104 with 32 bytes of data:

Reply from
173.194.37.104: bytes=32 time=40ms TTL=245
Reply from
173.194.37.104: bytes=32 time=41ms TTL=245
Reply from
173.194.37.104: bytes=32 time=40ms TTL=245
Reply from
173.194.37.104: bytes=32 time=39ms TTL=245

Ping statistics for
173.194.37.104:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 39ms, Maximum = 41ms, Average = 40ms

If you do, that's great because it means that the router IS talking to the internet so go to step 3.

If you didn't get those 'ping' responses then it would seem that your router isn't talking to the internet.

Step 3 - Are full internet services available?

This time, in the command window (which you've still got open) type the following...
ping google.co.uk
and press enter

Hopefully you should see something like

Pinging google.co.uk with 32 bytes of data:

Reply from
173.194.37.104: bytes=32 time=40ms TTL=245
Reply from
173.194.37.104: bytes=32 time=41ms TTL=245
Reply from
173.194.37.104: bytes=32 time=40ms TTL=245
Reply from
173.194.37.104: bytes=32 time=39ms TTL=245

Ping statistics for
173.194.37.104:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 39ms, Maximum = 41ms, Average = 40ms

If you do, that's again great because it means that not only is the router talking to the internet but that it's able to do all the stuff it needs to access web pages.

Sadly, it also means that you've reached the end of the road because the internet IS working fully, there must be something else stopping your connection and that's a REALLY big topic!




Wireless Problems
OK, we'll assume that you're here because it all works fine with a wired connection but you can't use your wireless link.

Again there are a number of possible causes...

Is the router wireless switched on? There should be an indicator light on the router, maybe with a symbol of an aerial showing that it's on. If it's not on you're going to have to refer to the section later on, "getting inside the router"!

Is your computer wireless switched on? In the case of laptops there may be a physical switch or button to turn it on or it may be done by pressing a function key (find the key - maybe with a picture of an aerial) and hold down the 'Fn' key while pressing this key.

Are you detecting a wireless signal? Assuming both ends of the wireless system are switched on, you should see an icon in the task bar of your screen (bottom right hand corner) telling you something about the wireless connection. Maybe it's saying (if you hover over it) "Not-connected, right click for more options". Equally you could look in Network Connections via the control panel as described in Step 1, "Network card not turned on". Right click and select View Available Wireless Networks. Hopefully you'll see your router there - if not and the router wireless is on, then you've got a problem that's just gone outside the scope of this article! If you can see your router then you ARE detecting its wireless signal!

Have you using the correct security details? In order to connect to your router (which SHOULD have security turned on!) you would need to provide a security key. Hopefully you know what this is and sometimes you'll find it on a label on the router itself (look for words like WEP key or WPA-PSK key), if not then you need to head for the section "
getting inside the router". Assuming you do, then all you should need to do is select the network you want to connect to and click on a 'connect' button and follow what it tells you to do. If all goes well, this will make the connection but if not, did you get the key wrong? Perhaps you need to move on to "getting inside the router"!



Getting Inside the Router

By "getting inside" I don't mean actually opening it up! The router is actually a computer in its own right and provides a web-like interface which you access with your web browser (hopefully FireFox, but maybe you're still pinning your hopes on Internet Explorer). If you're doing this because you can't get a wireless connection then, obviously, you're going to have to connect your computer to the router using a cable!

You remember from step 1 you discovered the IP address of the router ... you typed ipconfig and got some information about the gateway address? Well that's the address you'll need now. In my example it was 192.168.0.1. In the address field of your browser (that's where you normally type www.somewebsite.com), type that address, eg. 192.168.0.1.

You may be presented with a status page but most probably you'll be asked for a user name and password. The trouble is that I don't know what they are and you almost certainly don't either! All routers are different and the password may have been changed by whoever set it up (even so, all would not be lost), however there are a number of well known things to try...

with a user name of 'admin', try it with no password and then with 'admin', 'password' and 'root'. If none of those work try with a user name of 'root' and try all those again. Also, if you've got broadband from sky, the password might well be 'sky'.

Hopefully one of these combinations will have got you in so we'll look at what you might be able to discover but if you're not able to get in and don't know the password you may have to reset the router and setup all your broadband details all over again. This means you'll need your broadband account name and password (and if you're with AOL you'll need to know the screen name that was used for the router connection - that's different from your normal AOL screen names!). Once you've gathered all that information then you need to reset the router and, again, routers have different ways of doing this so you probably need to find the instructions that came with it (which MAY tell you), otherwise you could find that information on the internet - if only you had a connection. WARNING if you don't know your broadband password, step away from the computer! It's presumably stored in the router and there are usually ways of retrieving it - but not if you've 'had a go' and changed it!

Inside the Router you'll see all manner of things but because they're all different, they all look different so you'll have to just poke around and see if you can find something that matches what I'm describing. I'm basing my descriptions on a Netgear DG834 router, which is fairly common.

Information about the internet connection

Probably something about this willl be shown when you forst connect to the router but if not look for links called "status". You'll see references to WAN and ADSL - that's the internet connection - and LAN which is the connection between your computer and the router.

Amongst the various status items you might find 'Connected' which probably means that it thinks it's talking to the outside world. More importantly you should find things like 'Gateway IP address' and 'Domain Name Servers' (DNS Servers) and these should be listing IP addresses a bit like you've seen in step 1, for example 62.241.161.237, 208.67.222.222 and
208.67.220.220. If you are getting those type of numbers then it almost certainly IS connecting OK.

Wireless Settings - Is it ON?

Often under a heading of 'Advanced' or maybe somewhere else there would be a section about the Wireless. The first thing you need to check is that it is actually switched on. Look for something like 'Enable Wireless Access Point'.

Wireless Security Settings

Somewhere you should be able to get at the wireless security settings. These will allow you to turn security on or off and, if on, will usually allow you to select the type of security WEP, or WPA-PSK. Presumably it will already be set and you should be able to see the key. If not, you can always save a new one. A WEP key uses the characters 0-9 and A-F and is not (normally) case sensitive, a WPA key allows you to use any characters you want and IS case sensitive. Also the length of a WEP key is determined by the WEP type:- WEP 64 bit requires 10 characters, WEP 128 bit requires 26 characters.



Well that's about it. Hopefully after all that at worst you'll have some idea where the problem lies and, at best, you might even have fixed it!

Fell free to post any comments about this article and let me know if any bits are confusing. This isn't a particularly difficult area but it IS rather complex - there are lots of bits to it.

Eventually this artcile will get put on my website at www.callonken.co.uk with all the other useful stuff.

Saturday, March 14, 2009

Windows XP - The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE

This article is not for the faint of heart! It is very technical and may help those doing technical support out there. If you're in the 'normal user' category, I wouldn't suggest trying this yourself! You could totally kill your system!!

The problem:

You're getting the BSOD and a message indicating that a registry file is corrupt. There are a number of these messages and you may have found your way to the Microsoft knowledgebase article KB307545. This outlines a rather long winded and very convoluted procedure to try and effect a repair using the tools that Microsoft provides. It also requires (1) that it is not an OEM installed OS and (2) that you have an original XP dsk availble. This solution doesn't have either of those contraints!

The Solution:

What the KB article is all about is getting hold of the latest backed up set of registry files and replacing the broken ones with these. In order to do this you need to start up the machine using something like Ultimate Boot CD (search Google for UBCD or UBCD4Win) - anything that allows you to boot up the machine and get access to the file system.

The files you need are the ones which are saved during a restore point creation and can be found in a folder called something like...

C:\System Volume Information\_restore{B33F2D25-8664-459C-AE54-C8D699E59CB4}\RP180\snapshot

(RP180, for example, is the restore point you want to use - look at dates and times of the folders).

There are 5 files (registry hives) that you need to copy over and these are

_REGISTRY_USER_.DEFAULT
_REGISTRY_MACHINE_SECURITY
_REGISTRY_MACHINE_SOFTWARE
_REGISTRY_MACHINE_SYSTEM
_REGISTRY_MACHINE_SAM

They need to be copied to where the registry files live and this is C:\windows\system32\config.


Before replacing the old registry files (DEFAULT, SECURITY, SOFTWARE, SYSTEM and SAM) it's a good idea to move the old ones to a new folder somewhere or rename them (for example rename SAM as xSAM, etc) so you can go back to where you were if all goes belly-up!

Then rename the restored files to have the correct filenames, for example, rename _REGISTRY_MACHINE_SOFTWARE to be SOFTWARE.

And that's it! What you've done is perform a system restore without using Windows itself.

Of course, I've left out a lot of "how to" details that you ought to know already - like how to navigate through filig systes, copy and rename files, etc.. Like I said, this is a technical article and if you can't fill in the gaps yourself then you shouldn't be trying this!

Just one pointer though... if you're doing this from a Windows boot you may have problems getting into the "System Volume Information" folder because of access rights. If so, have a look at the Microsoft KB article KB309531 which describes ways (including use of CACLS) to get access.