Okay, so I installed l-ubuntu on virtual box (which is installed on windows 7-64 bit) and then on vmware player successfully to learn some bash programming. Then, I connected my computer to the internet with an ethernet cable. When I disconnect the ethernet cable, I lose my wifi connection on the guest OS, ie windows 7. But, I can connect using an ethernet cable. Now I have to sit near my wireless gateway :P
I noticed that this problem was solved when i uninstalled virtualbox. But, it happened with vmware player too. I tried using windows "troubleshooting", but it does not work.
How do I get out of this mess ? I need virtualized lubuntu badly and with a working wifi connection.