Is there a good application to track incoming and outgoing network packages for Windows 7? In other words monitoring my PC's network traffic.
For detailed packet monitoring, WireShark is probably what you want.
WireShark is free and open source.
If you'd like to see which applications are using your connection in detail, NetLimiter Monitor is great.
NetLimiter Monitor is freeware.
Both applications are Windows 7 compatible.