USRobotics USR3453C Courier 56K V.92 Ext Modem driver

We have exsi 5.1.  This is a windows server 2008 64 bit enterprise edition virtual server.  We are using a perle device that passes the com port through to the server.  That all works fine and it's been tested by perle'a tech support.  We did this exact same set up on a windows server 2003 virtual server and all we need to do was go to control panel and add the modem manually.  We just downloaded the us robotics driver for the server 2003 and browsed to it.  It added the modem and the modem worked fine.

We are now replacing that server and we have installed the perle device on the new windows server 2008 64 bit.  Everything is setup the same way and we want to add the modem manually through control panel.  There is no 64 bit us robotics driver for windows server 2008 to download.  

I called us robotics and they said the modem is compatible with windows server 2008 64 bit but it doesn't use the us robotics drivers.  It uses the windows update drivers that it pulls automatically when you plug in the modem to the OS.

So is there any way for me to get these drivers that it pulls automatically so I can add them manually.  If I get those windows drivers it will work.  I just don't know how to get toes drivers.

Thanks

sorry typo .. those drivers

Sorry for the confusion.  Yes the com ports are working.  I've already done this with putty and all is working.  I just need to add the driver.  Need to manually download the driver the Microsoft automatically installs for us robotics 3453C external modem that will work with windows server 2008 64 bit.