When we first set up our wireless network, everything seemed to be ok. It was when everything seemed to slow down that we started to look into wireless security.

1. MAC Address filtering

This was the first thing we tried - by giving the router a list of the MAC addresses of our computers, it was supposed to allow them to connect but refuse connection for all other machines. Unfortunately, due to a bug in the router itself, it kept disconnecting us, forcing us to reset the router each time (this only affected the router when it was set to use 802.11g. It worked ok with 'b' only).

To find the MAC address of your computer on Windows XP, open a command window and type: ipconfig /all The MAC address is listed as 'Physical Address'.

2. Broadcast SSID

With this enabled, the router is telling the entire world (well, the bits that are within range) that there is a wireless access point available, and come over and steal our bandwidth. With this disabled, a computer needs to know the name of the network before it can connect to it.

The first thing to do is to change the name of the network. The default name in the router might be the model number or router type, which would be easy to guess and not at all secure. After that, disable the 'Broadcast SSID' (or ESSID) option. The chances are that your computer will now have been disconnected (unless you're being sensible and making these changes while physically connected using a good old fashioned network cable).

The next step is to let Windows know the name of the wireless network so it can connect. If the wireless card's own software is managing the connection, there should be an option somewhere to specify the network's name. Otherwise, you'll need to open the Wireless Network Connection icon, click on Properties and then select the Wireless Networks tab. From there you can add a new network and provide the SSID.

3. Encryption

This is the most secure method - it will stop people connecting to your network and will also prevent anyone from evesdropping on your data.
Again, this is a two stage process: Setting encryption on the router and then on each computer which needs to connect. The exact method will vary from one router to another but one of the standard methods is WEP or Wired Equivalent Privacy. On the router, select WEP 128 bit. You'll then need to provide the 128 bit key - either by typing in a series of hexadecimal numbers or by providing a word of phrase and having the key generated for you. Whichever method you use, you'll need to make a note of the key before clicking 'OK'.

In Windows XP, the encryption settings are in the same dialog box where the SSID was specified above. Network Authentication needs to be 'Open' and Data Encryption needs to be 'WEP'. Then type the encryption key in the boxes and click OK. With any luck, you'll have a nice secure wireless network.

For the last week or so, my wireless broadband has been really slow. At first I suspected the broadband itself but the downstairs computer was fine, then I suspected the wireless router but the other upstairs computer was fine as well. It looked like it was just my PC which was having problems. The connection was very slow and would occasionally stall causing any downloads or web pages to time out.

I tried a few things to attempt to fix it:
Reset the router and set it to use a different broadcast channel and transmission rate.
Reinstalled the wireless card drivers on my computer.
Removed the wireless card from my PC and installed it in a different PCI slot.

None of these made any difference. It wasn't til I removed my bluetooth dongle that the network speed got back to it's normal rate. It's very strange if the bluetooth has only just started to interfere because it's been connected to my PC for several months with no apparent problems until recently.