The LINKSYS WRT300N is a standalone device, there are no software/driver needed on your PC for the router to work. However, there is an easy Setup Wizard that is in the CD that normally comes with the unit.
Unfortunately, Linksys did not make the specific Setup Wizard (Version 1.3) for the WRT300N available online. However, if you care to try the Setup Wizard for a WRT54GC, it may downloaded from the LINKSYS ftp site here
. I used to have a WRT54G and I did make use of the Setup Wizard for that model. I upgraded to WRT300N. The setup wizard for the old WRT54G worked likewise on the new WRT300N.
Alternately, the WRT300N can still be configured without the CD or the Setup Wizard by logging into the Configuration Page (192.168.1.1). Remember to use LAN interface when setting the router (as shown in the connection diagram) and set your PC to an IP Address of 192.168.1.2, Subnet Mask of 255.255.255.0; Follow on screen instructions and enter settings/configurations manually.
Hope that this be of some help/idea. Pls post back how things turned out or should you need additional information. Additionally, if you still prefer to have a copy of the original WRT300N Setup Wizard, pls include your email address that I may send it to you as an attachment.
Good luck and kind regards.