John T wrote:

Generally, if the PC recognizes the RAM, it should be able to use it.

Well, yes an no. Windows XP in its standard incarnation is able to manage up
to 4GB of RAM, however, it will assign a maximum of only 2GB to a single
application. So, if you only run one memory-hungry app at a time, more than
2GB won't do much for you.

Anno.