I just installed VectorLinux on my sister's computer and she uses wifi for the internet. The card was automatically detected and configured (AWESOME) and it connects to the router, but once the computer is rebooted it doesn't automatically reconnect and she has to use the wifi radar app every time.

How do I set this Wifi connection as the default one and make it automatically connect?

I had the same problem and solved it by adding this to the end of /etc/rc.d/rc.local:

It works beautifully. Be sure to include the "&" at the end or it will hang on boot. rc.local is the last init script to run at boot. My edit starts the WifiRadar daemon at the end of the boot process. WifiRadar then looks at all the wifi essids you have previously setup and scans to see if any are available. When it finds one it automatically connects to the strongest available. If it finds none available it doesn't try to bring up the wireless network which makes it nice if you take the laptop out of the range of your wireless access point.

Thanks I'll try that.

wifi-radar doesn't work. The only thing that does let it connect is vwifi but with that I haven't found a way to connect except to run the program and enter the SSID manually.

Is there any single command (like wifi-radar -d) for vwifi? (like vwifi SSIDNAME)

You can use iwconfig to connect
see man iwconfig for information.
replace eth0 with your interface name if needed

Try that in a terminal as root... if it works, add it at the end of your /etc/rc.d/rc.local file