Hi
So you had Home on it before and now its Pro but the other machine is Home ?
Here's what I did, on the home machine turn off "Simple file sharing" its in explorer tools >folder options >view, at the bottom of the list, now go into the firewall settings on both machines and make sure "File and print Sharing" is enabled, even though its not really important make sure both are in the same workgroup, I think Home uses "MSHOME" and Pro uses "Workgroup", then set the folders you want to share on either machine and you should be good to go.
Regards