I was told my a radio shack guy who knows a lot about computers that I don't need any cable or extra stuff to connect my laptop with windows 7 to my desktop with xp. I need to creat homegroup which I did and make a cd for the other computer but the only option it gives me is making a floppy, which my laptop doesn't have???
Your Radio Shack guy was overestimating your knowledge.
It depends whether you have a wireless connection on both computers (or perhaps one is connected by wire to a router).
Frankly, the simplest way is to buy a crossover version of an ethernet cable and run it between the networking ports of the two computers.
Here's the rest of it. If you can't grasp it I suggest you get a friend to help. Windows Help will fill in some of the gaps.
Write down the names of both computers (Control Panel, System, Computer Name).
In My Computer select relevant Folders and Allow File Sharing. Disable the firewalls in both computers. Then run the Networking Wizard (ignore the floppy thing). Go to My Network Places and Add a New Networking Place.