Home network

HI,
I have a problem in networking. I managed to wirelessly access printer from my laptop to my desktop and other files. But I cant access from laptop to pc my files only printer I can. Why is this so? I tried disabling firewalls and it doesn’t work. Both run xp. When I click on the laptop in the same work group my desktop comp it says I don’t have permission and I should contact administrator and both comp are logged as admins. As we are connected via router why is it that I can see my laptop files fine but I cant see on my laptop the files from desktop?
PLEASEEEEEEE HELP