Hmm... Im not sure if I should start playing PC games again just for LIMBO until I get a new computer sense my computer will be turning 4 in a few weeks or so but oh well here goes my questions. I can understand why you need more then 1 Disc but is the game fully installed so you wont have to use the disc(s) or how does that work? Do you need to switch the disc(s) like PS1 games? Depending on the game would it lag, crash, or becomes unplayable if I dont have the right requirements? (the main reason why I stopped PC gaming in the first place years ago) Hmm... I think thats all I have for now.
First off, these questions are a bit over the place so sorry if I seemingly don't understand what you orignally asking, but i'lll try any how. If a game on the PC has several install discs, you won't need to keep swapping discs in and out once you've fully installed it the first time. After that, the disc is only read to confirm that the PC is allowed to execute the Program of the game you played. So only one disc will be required to put in the disc tray but will still be needed so you can't simply sell on the game, if any it'll be disc one where it'll accept you but I think all would work fine. PC gaming is only worth getting into if you know more about specs, requirements and the general differences between PC and console gaming, which is a steep curve if you really don't get it. Find a friend who has an actual PC for gaming who is knowledgable and ask them to show you theirs. Easiest way, I think.
PC gaming has never been as accessible as console gaming. As PaW said, you really need to know a good deal about computer specs to even consider starting it. I would recommend seeing if you have any friends that know a lot about computers, they don't really even have to be a gamer, but preferably someone that knows how to take them apart and put them back together. You too should also try to get the basics down, I made this post a little more than a year ago (so some of the info is a bit outdated), but it should give you a slight starting point. If you have the ability to play a game on a console and things like modding aren't important to you, go for the console. A PS3 costs $300, while a budget gaming PC will run you around $700. I don't do very much of any PC gaming (haven't got the cashmonies) but others would say it's worth the price, but it is an investment.
I think it would be better if you could give us your price range, and the game you're hoping to play.