Wow, you've revived a really old thread from 2007!
Anyhow, there's a command (whereis) that will tell you where ndiswrapper is installed. It may be in /sbin or /usr/sbin, and you may need to log in as "root" to use the ndiswrapper command.
Have you looked at the dmesg output (dmeg | less) to see what the kernel "thinks" about your wireless card? Some Netgear wireless cards use the Broadcom chipsets, and, if your WG511v2 is one of those, F10 will have loaded the b43 driver for it, and all you'd need to do to get it working is to run b43_fwcutter to "cut" the proprietary firmware from the INF file