Can Ubuntu lan with windows friends

Yes, you can config a LAN with Windows machines. I think this link should help : http://askubuntu.com/questions/107208/how-to-setup-a-lan-between-ubuntu-and-windows

so will this work also if i wanna play games with friends? sorry i sound stupid but ive never used ubuntu before

The LAN standards are such that a wide range of devices can co-exist happily on the same network. You can have Windows, Linux, Network printers games machines such as PS3 all connected at the same time.

The link provided in post #1 shows how to share files between Ubuntu and Windows.

To play games over the network you will need to find network games which exist on every platform you intend to use as in general games send only enough information to each other to let the other computers playing the game know what all the players are doing.

There are multi platform games so it can be done however as things stand there are fewer high end games available for Linux than Windows. I'm sure this is purely down to market share and will change as Linux becomes more popular: there are more Windows users, so developers concentrate on Windows more. Some, but not all, Windows games can be made to run in Ubuntu using WINE.

I hope this clears things up but don't hesitate to ask if you have more questions: We were all newbees once.