Device eth0 does not seem to be present

This blog has good info: http://aaronwalrath.wordpress.com/2011/02/26/cloned-red-hatcentosscientific-linux-virtual-machines-and-device-eth0-does-not-seem-to-be-present-message/

how to shutdown windows 8

Press the Stupid Window Key and the 'i' at the same time.  then click the power icon on the panel that appears.

... sorry I don't have annoying ads and didn't write a 5 page article about this subject

windows 8 sucks. I HATE 8

the cure for the crap UI of windows 8 is the same as is it was for all the other shitty microsoft products : http://cygwin.com

undefined symbol: rb_encdb_declare when building ruby

You can do the rvm thing but a quicker approuch is to use --disable-rdoc option when you run configure