PC WORLD investigates the hidden costs of upgrading to the Windows Vista OS. Because both time and money are on the line in any OS upgrade, people interested in upgrading to Vista should be aware of the high cost of hardware.  If one plans to upgrade to Vista, users might have to initially outlay additional money to upgrade their system’s RAM. While Microsoft says you can run Vista with 512 megabytes of RAM, it simply isn’t worth running Vista on a machine with less than one gigabyte of RAM. In addition, even if one has enough RAM, the graphics card may not be up to par, as Vista is very graphics–orientated–which could mandate another upgrade. Furthermore, Vista only installs via DVD, so if the machine lacks a DVD drive, another purchase and upgrade is necessary.  Finally, in order to run Vista and save room for files and other media, a user should have at least 40 GB hard drive capacity, with 15 GB free for files. Now consider that in addition to purchasing these upgrades, it also takes time to install them and make sure they are working properly. Considering these issues, upgrading to Vista could potentially have a lot of “hidden costs” in terms of both time and money…

http://www.pcworld.com/article/id,128930-c,vistalonghorn/article.html