I didn't know. In any case lsmod is a standard Linux command, not something specific to Vector. Also bigpaws' link points me to real HOW-TOs now. I don't know why it changed (maybe he changed it) but the information there, which does answer the question well, is probably not for newbies. Anyway, follow the link and see if you understand which driver your card uses and see if you understand the Slackware instructions. Vector Linux is based on Slackware.
To determine if the driver is loaded:
Open a terminal window and at the command line just type in:
lsmod | grep rt25
Post the results here.