Omg, i'm in big trouble:

I found out that there's no way i can change my connection settings (like IP, DNS and protocols). After i have opened Network Connections window, i can't make right click on a connection. If i do that, the particular window will freeze and only solution to close it is via Task Manager (End Task). Also.. when selecting a connection and then clicking 'Change settings of this connection' on the left, nothing happens.

What should i do now? :/

Windows XP SP2.

Done VIA the commandline

netsh interface ip set address "<connection name>" <static or dhcp> <ip address> <netmask> <gateway> <metric>

Where connection name = local area connection, or local area connection 2, depending on the interface you want changed.

Also, the metric is number of hops to the gateway, usually 1.

Yeah, but that actually does not solve the problem. It's just an alternative. And instead, i want to access the properties via gui. In fact, i just need to check if File and Printer Sharing for Microsoft Networks is installed and enabled.

Reboot to Safe Mode with Networking make sure you can access it there if you can it is likely something causing the system to hiccup when you try and access it. Background service?

http://support.microsoft.com/kb/181966