Connection Failed - Firewall Errors Detected

Problems connecting to different services and an online game. Examples:

1.) "Connection timed out" in Teamspeak 2. (debug log not really yielding much useful information).

2.) Torchlight 2 reported "Connection failed - Firewall errors detected."

- almost all other online applications work just fine (including voice over ip and games) What I've tried (without any success):

1.) I could connect in either case using my old laptop! Thus it works on a different computer, from the same network, at the same/similar time. Thus I concluded it must be somehow related to this laptop (its a new laptop).

2.) The TS2 server & entered information is 100% working, same applies to torchlight2 - also latest updates installed and of course the game is totally legal.

3.) Windows firewall: all the mentioned programs are on the allowed list. Also check whether its correctly set to "home network". Futhermore I also tried disabling the windows firewall entirely.

4.) No other firewall program in use.

5.) Check all programs I know of which might be related to network traffic (e.g. Qualcomm Atheros Killer Network Manager - disabled it).

6.) Tried both, wireless and ethernet cable connection.

7.) I even tried running the game, torchlight 2, via Tunngle (explained in a layman's words: a program that simulates Lan over the internet).

Some Information about my system:Its a new laptop. Network card is labled as "Killer e2200 PCI-E Gigabit Ethernet Controller.Runs Windows 7 and did start out empty: i.e. I installed every single program running on the machine and as far as I know none of them should have anything to do with network. Virus scanner is the lastest version of AVG free (no firewall included).