And what files did you share? Are you both members of the same homegroup, have you set that up?
Some details kind of required -- what firewall are you running, built in 3rd party?
Your machine does not magically share your folders unless you tell it too.
Click F1, type in share files in help.
My system: ELLIOT-PC
Her system: TRIIN-HP
No firewalls on either PC (and it's disabled on the router).
Regarding general folder sharing:
On ELLIOT-PC, I shared a folder by going to the folder Properties, Sharing, Advanced Sharing... then I ticket "Share this folder".
TRIIN-HP can't see this (or anything I share) because within Network, she gets "Windows cannot access \\PC-NAME"
On TRIIN-HP, I shared a folder by going to the folder Properties, Sharing, Advanced Sharing... then I ticket "Share this folder".
ELLIOT-PC can access this folder perfectly.
We are part of the same HomeGroup and we appear to each other when we click HomeGroup on the Start menu and can also see the folders inside e.g. Music, Videos but when we try to open those folders, neither computer does anything (no message, just the spinning cursor icon for three seconds).
Extra information that may help: