112Mb is simply a 128Mb module with 16Mb used for onboard graphics. Adding more RAM will NOT mean you can't reinstall the system, the reinstall will work perfectly. 128Mb is not enough to run Windows XP efficiently, and you should definitely add more.
Thanks Catweazle :!:
I heard the same explanation talking to an expert who mounts PCs. I´m thinking of changing to a new computer with 2,4 GHz and 256 MB RAM, and a 40 G HD. It´s funny that the configuration I have 112MB for Windows XP came in a "brand" computer. :evil: