@albynas Pinging the external (public) IP fo your modem will give you destination host unreacheable. Have you tried to ping another IP? ping www.google.com
The reason why you can't install it is because it tries to install a printer driver that it uses to output the pdf files which is not compatible with Vista. However, as the other have said in the previous posts an updated version might work. Only thing is to check whether this new version is compatible with Vista or you'll waste your money on a program you'll never use...
When you plug it in, the PSU capacitors get loaded with power. Since you don't turn on the PC, when you unplug it the PSU light is discharging the capacitors, that's why you see the blinking getting slower and slower.
Actually yes, you can. Windows stores your cached profile and credentials and will let you authenticate on the machine even if it is not connected physically to the domain.