Hello guys! I've been looking all over the web about this but unfortunately couldn't find much. I have a 21.5" iMac as the title suggests and I would like to also use it as an external screen to my PC tower. Also note that this is a 2010 model and came without the Thunderbolt port. I've heard all sorts of opinions such as "Not gonna happen" but I've also come across some people saying that it is possible through ethernet cable and some software. However everything I've encountered was quite misty, so I thought I'd pay a visit to the temple of apple solving issues. Any specific answers are more than welcome!