These limitations are due to the Win32 memory model. Win32 memory model was concepted in early 90's, when desktop machines were delivered with 4MB; at those times, 4 GibaByte was a really huge amount of memory. Microsoft decided to divide the addressable space (4GB) in two, 2GB, sections - one for the OS, the other for applications. Therefore, no Win32 application shall access more than its 2GB share of memory. Under this model, a machine running with 4GB is using intensively the 2GB share for apps and the first giga of the OS - the second is not used, in most desktops. Microsoft has noticed exactly this: the OS rarely uses completely its share of 2GB; so, they decided to support PAE (an hardware feature), to divide memory differently in 3GB for applications and 1GB for OS. However, few applications are prepared to PAE (mostly, server applications), so, the probability of having an app using the extra 1GB is relatively small. So, under the PAE model, you usually fall on the classic Win32 model: apps using franticly their 2GB (because they were not developed to take advantage of the extra giga), and OS kernel running in 1GB.

I believe it makes no sense to give a gender to computers, in English. However, they have gender in several other languages: German: Rechner (masculin); French: ordinateur (masculin); Portuguese: computador (masculin); Spanish: ordenador (masculin), or computadora (feminin).