so i'm attempting to use my laptop as a second monitor mostly so i can do that cool thing where you drag something from one screen to another, but so i can have, say, itunes or tweetdeck always open and visible. or stream football on one etc etc.

ANYWAY, seen as my computer doesnt have two vga ports, i've got:

-one vga to vga cable connected from my pc to my main monitor
-one hdmi (port in the back of pc) to vga (back of laptop) cable

but it's not displaying that two monitors are set up - in fact i'm using my laptop as usual now as nothing has been detected.

different operating systems and other possibly niggly issues.

eventually i'll join a geeky tech forum for these questions.