It's your company firewall blocking outgoing requests on port 30015. Seems they allow port 22 which is used by putty. Changing your windows 7 firewall settings should not have any effect to my knowledge (I am a Mac user, so take this with a grain, better a ton of salt), as it is meant to protect you from incoming traffic - but you can try to disable it completely...
If you know Linux, or want to get into it, you can setup port forwarding on your HANA instance and use an open port (e.g. 80 which is used for http and open if you are able to browse the www) to connect and then in your HANA box forward it to port 30015. If you don't know Linux and networks, it's more like your first open heart surgery with a Swiss Army knife, though - http://scn.sap.com/thread/3293751 has some basic information on the necessary steps
Cheers
--juergen