I use a Mac and have Wi-fi at home based on Apple's AirPort Extreme. I want to set up a system that allows me to listen to my music in different rooms. How do I do this?
John, Pok Fu Lam
DQ: You already have a basic system in place. You could set up a more elaborate system yourself but the odd problem could arise, such as walls that prevent the signal getting through. You may have to boost the signal with a compact AirPort Express base station. For help setting up wireless systems on a Mac, visit www.mac-forums.com/forums .
If you prefer not to fool about with the technology, there are other possibilities. A popular solution is Sonos' (www.sonos  .com) multiroom music system, which can project music from a PC or a CD player.
You must decide if you want to construct a wireless, multiroom music system yourself, get a ready-to-install system or have a professional set the whole thing up. Computer shops in Hong Kong don't normally do house calls but you can always ask.
When my Sony Vaio laptop went on the blink, I used the recovery disc that came with the machine. Now all my personal data is gone and I cannot connect to my home Wi-fi router, which keeps saying 'enter: 18.104.22.168'. What should I do?
Name and address supplied
DQ: When you use the CD-Rom disc that comes with a computer, you are returning to the original settings of the machine. This means you could lose all personal information, including data needed to connect to your Wi-fi router.
The router itself probably still contains the information you need. That string of numbers you are getting is called a class C address, which is typical for such routers. It will not connect you directly to the internet. You can establish a link with the router by connecting an Ethernet cable from your computer to the device. You should be able to follow the instructions at that address to connect the laptop to the internet via your wireless local area network.