Anup, have you set upt the networking wizard in XP on these machines, it makes no difference if they are virtual or physical as long as your networking for the virtual setup is fine.
another thing I need to know is if you are using Remote desktop and do you mean when you browse for machines or are you refering to browning my neighbourhood network. if you mean RDP browse then you will need a managemnt software to be able to see all of your machines in there and also you will need to have anabled remote desktop from computer properties. try juts entering the ip address in Remote Desktop and see if this connects
also your default gateway should be the same for each machine on the same subnet, will not really make a difference if your only connecting to the one machine on the same range but if you try anything different will be a problem unless you have three default gateways that is.
also try accessing the share by ip \\192.168.10.7 and see if this makes a link and not just a ping.