Depending on the motherboard you will see some 2.0 to 3.5GB reported. With the latest service pack Microsoft tweaked their OS to report (but not use) 4.0GB because too many CONSUMERS were calling in to ask "Where's my ram?"
Nothing has changed in memory support here since the year 2000. 32 bit Windows and all the articles still apply so I'll stop here.
Sounds like a dumb question, I know, but I have seen various conflicting information and wanted to see what the real deal is. I have seen from 3-8GB mentioned on various sites.