You can get stuck in all sorts of places.
You didn't mention what is in-between you and the win 7 machine, so I'm going to assume you're on something bigger than a lan.
When I get stuck like this, I'll use Trace Route (tracert)
For example, say between you and the server is 3 routers: A, B, C
Trace-route and ping use the same protocol (ICMP).
Ping tries to send a direct message from you to the server. Trace Route sends:
- you to router A
- you to router B
- you to router C
- you to destination (in this case, your Win 7 machine)
(You can confirm this by watching the packets in a packet sniffer)
If trace route doesn't work (ie doesn't get from you to router A) Then you know that you are blocking ICMP traffic.
If it gets to router B, but then stops, you know that router C is block ICMP.