trying to replace xandros with ubuntu 9.4

[ladybluballs]

I have 2 hard drives installed.windows vista on 500gb and xandros on a 120gb set up dual boot.I have lockup problems with xandros and want to install ubuntu in its place I can;t find any option to let me put it on the 120gb that now has xandros so I tried to install it on the 500gb with vista the install at first looked like it was going to install then at the last part of install it said looking for other os system then it said uninstalling packets and its back just like it was to start with vista and xandros thanks in advance

[ladybluballs]

I have 2 hard drives installed.windows vista on 500gb and xandros on a 120gb set up dual boot.I have lockup problems with xandros and want to install ubuntu in its place I can;t find any option to let me put it on the 120gb that now has xandros so I tried to install it on the 500gb with vista the install at first looked like it was going to install then at the last part of install it said looking for other os system then it said uninstalling packets and its back just like it was to start with vista and xandros thanks in advance

I really really need help,do I need to unplug the 500 gb hhd that has windows and install ubuntu on the 120gb that has xandros and then hook both hhd back and then try install again to get the boot grub configured?