Ubuntu - wireless - Windows 7

i have a question...

my cousin has two computers, one old one downstairs is running Ubuntu 9.1 and is connected to the ADSL, upstairs brand new i5 running Windows 7 Home Premium... he would like the upstairs PC be able to access internet via a wireless connection.

if we hook up a wireless router (D-LINK wireless N router DIR-615) to the old PC (Ubuntu) will it "speak" with the one upstairs to allow it to access internet?

PS. also will the PS3 upstairs be able to access the DivX files from the Ubuntu PC ???

The upstairs pc will talk to the router, not the other computer for internet access.
So you could hae 5 different operating systems running, as long as they can talk to the router they will be fine.

As for the PS3 talking to the Ubuntu PC, yes it can be done. I dont have the names of the programs at hand, but a quick google should come up with those.
I remember when I was looking around there was about 3 or 4 highly reccomended ones to use for this application.

Yeah, that can work... but why not just hook up the wireless router directly to the ADSL modem and then connect the Ubuntu PC to the router with a cable and use wireless for the PS3 and i5? Would be arguably faster than using ICS on the Ubuntu PC and would also allow the PS3 and i5 to have retain the internet even when the Ubuntu PC is turned off.