Currently Being ModeratedMar 23, 2012 9:49 PM (in response to Danielwinnie)
A iMac used as a display is referred to as target display mode. It can only be connected to another thunderbolt mac via a thunderbolt cable. So that's two reasons why you can't do what you want (connecting to a pc, and trying to using vga).
Currently Being ModeratedApr 9, 2013 5:58 AM (in response to GiPhone)
Only if the PC is 100% compatible, the PC has to have Thunderbolt output and have the ability to send a video signal through the Thunderbolt output port. To be honest I haven't seen a PC that does that yet, but who know they may be coming.
Currently Being ModeratedApr 9, 2013 6:07 AM (in response to rkaufmann87)
I like to use it with my MacBook Pro (with Thunderbolt display) ..
and also with my TV decoder (STB = Set Top Box) through a HDMI to Thunderbolt converter.
This converter worked correctly with my okd iMac 27" .. but it seems to doesn't work now ..