I would not settle for merely 256Mb of RAM either. Windows XP works very efficently with 512Mb of RAM. That's the amount I personally consider necessary. In a system with multiple user accounts, and on which multi-tasking is frequently carried out, I install 1Gb of RAM.

It does not surprise me in the slightest that PCs get sold inadequately confugured by 'Name Brand' manufacturers. Although the quality of support service is generally extremely good with such systems, they are notorious for being considerably more expensive and underpowered in comparison to 'White Box' systems.