First thing, get to know where the problem lays. You may wanna try to disable fully your local Windows FW (including your personal settings and the so-called "domain" settings). If the trick works, the problem is with FW filtering.
If not, the problem is somewhere else. There are numerous questions to understand exactly what's happening in that case, including:
- are you behind a router? any FW on the router?
- any NAT?
- etc.
hth.