Try this.
On the PC, share the folder that all your photo's are in.
On the PC, create an account for the same username as the one you use on the Mac.
On the Mac, set "Allow windows Sharing" Fill in the rest of the questions under the accounts button
On the PC, grant that user name administrative access to the shared folder.
On the Mac, on the menubar, click on Network.
The PC, should be visible.
Double click the PC icon, log onto the PC using the name of the account you just created, and the password.
The shared folder should mount on the Mac desktop. Drag and drop from there.
Alternative, create an account for the PC usersname on the Mac.
Do the "all windows sharing" thing.
On the PC, Map a network drive. Enter the IP address of the Mac. Enter username and password. The mac should now be an attached network drive on the PC