GNOME and KDE, the most popular window managers, are resource hogs. Period, end of story. I wouldn't even dream of running them with less than 128MB of RAM. Just about any distro would would suffice for your purposes, but I would not install GNOME or KDE and would try something like
Fluxbox. It runs well with 48MB of RAM on my Pentium 75.
As for Wordprocessing and Instant Messaging, they won't be problems if ya pick up a copy of OpenOffice and Gaim.
http://openoffice.org and
http://gaim.sourceforge.net
Most older DOS games run just fine under DOSBox, so that shouldn't be a problem:
http://dosbox.sourceforge.net
As for the WLAN card, look into the Ndiswrapper project, that lets you use Windows wireless card drivers in Linux:
http://ndiswrapper.sourceforge.net
I noticed that you downloaded DSL. It is a good distro, but a bit limited.