Thanks for the reply!
I cant really think of any software that will use the wi-fi, I have tried closing all the internet required programs to see if that makes a difference, but it didnt.
When I removed the battery from the laptop, LFS worked ok with the power supply plugged in but when I put the battery back in, it disconnected after about 15 seconds.
I looked at the 'Networking' tab in 'Task manager' while plugging and unplugging the power supply and it didnt 'jump'.
I tried changing the 'Minimum power consumption' to 'Disable' (i assume it is the same as the XP version of 'power saver mode' in that menu) and it didnt do anything to the wireless that i can see