How do I access the information in my pc using my network connection?

I have Windows XP Pro desktop hooked up to the router and Windows 7 going wireless. I want to access my desktop. I have the network set up so that I can go online with my Windows 7 laptop, but I don't know how to get to the information on my desktop.How do I access the information in my pc using my network connection?Just makes sure both computers are in the same network workgroup (which is tricky on a Win7 machine so look up a tutorial) and make sure the files on your desktop are set to be shared.

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