VXD questions…

I recently installed a cable modem…
Since then I am getting this message when I start windows that Vredir.vxd and Dfs.vxd are missing from the registry/startup.ini
i have no idea what these might be?
also got a message that something vxd is missing and also get the blue screen of death here and there…

I had some problems with the intial installation, although now the cable modem is working. I had disabled and unstalled my old 56k modem. I have since reinstalled it just to be safe..Any help would be great, Thanks Todd