Getting windows to work is a bit of a problem. Did it work before you upgraded to 8.1? Or is this a new setup?
The folders are shared on the TC if you set file sharing to on.
But in the utility have you
1. Set all names short, no spaces and pure alphanumeric.
2. Turned on the Guest account to read and write access.
3. Set the WORKGROUP
4. Open windows explorer and type in the address bar. Either the name or IP address eg
\\tcbroken or \\10.0.1.1
(tcbroken is a TC I have repaired.. it is supposed to be irony and I am waiting for it to fail again).
5. No response, open a command window and type
ping tcbroken or ping 10.0.1.1
You must have ping response.
Use ethernet not wireless.
Turn off all the firewalls and ensure the windows machine is located HOME not WORK or PUBLIC.. windows can automagically change location.
Good luck.