not technically true, but actually is possible. you can set apart an area of your HDD for swap where it is used in a fashion similar to ram, it's used in linux all the time, and is encorperated into windows as virtrual memory(though no partitioning is neessary) The only bad thing is that you can load half a gig of your ram almost instantly and it takes about a minute to do so off your HDD.
Go to control panel -> Performance and Maintenance -> System -> Advanced tab -> Performance, settings -> Advanced -> Virtual memory, change. Then click custom settings and put how much you want. Don't forget to click set. This will then take effect when you restart your computer.
adding more tends to decrease sytem performane though, because your system uses it allong with regular ram so EVERYTHING is slowed. it's really only good if you have under 256mb of ram.