Windows XP is reaching end of life in April 2014. This means that Microsoft will no longer support it, and will not be releasing any further patches or updates for it. From a support perspective this is not such a big deal as there are plenty of people that can fix issues with Windows XP, more concerning is the lack of security updates. You can bet your bottom dollar that hackers will be writing exploits to take advantage of this situation. So the options are to either buy a new computer or find a new use for the old one.  If the old girl is still going you may get some more life out of her by installing Linux, an open source operating system. This will destroy all the data on the PC so it is advisable to back this up into another PC or external hard drive. There are many variants of Linux, due its open nature, many organisations have customised  their own brand. To get an idea of the varieties available you can visit distrowatch.com. Currently they rank the top 5 distributions as 1. Mint, 2. Ubuntu, 3. Debian, 4. Mageia and 5. Fedora. They all have their pros and cons but you can be confident that any of the top 5 will be useful. 

I have found Mint to be one of the easiest Linux distributions. It comes pre-packaged with most things you will find in Windows and is very similar to Windows in general. You can even run a live CD and try it before installing it permanently to your hard drive. Be warned though that Linux and Windows are different systems so you will not be able to run the same programs on Linux. Usually you can find an alternative program that works much the same way. 

If you can't squeeze any more life out of your computer there are environmentally friendly ways of disposing it. The National Televison and  Computer Recycling Scheme has been setup in all states and allows you to drop off e-waste at certain technology retailers and recycling centres. For more information go to dropzone.org.au.