If I build a computer based around linux. Can I still play Microsoft products? Sorry. I don't know much about linux at all.. like could I still play Bioshock CoD 4 and other games?

Marius,

I have moved your question to a thread of it's own. Piggybacking your question on someone else's thread only leads to confusion and someone's question may go unanswered.

Thanks :-)

No you will not be able to install Windows-based software of any kind. Many applications have a free open-source Linux alternative.

I have Ubuntu installed but I dual-boot to Windows for my Windows-only games. Within Ubuntu many people successfully use Wine to run their Windows apps and games.

All sounds very confusing to me lol

There are a few of us that run Linux (not just Ubuntu) on this forum. While we don't get deep into config talk (the Linux forums and Google searches are great for that) we can assist you a little bit. What distribution were you considering?

It is true that you can't run Windows games while using Linux.
If you choose the Linux Operating System you can do what NeedKarma adviced (Wine) and follow instructions or you can download some other free software made for Linux (games, jukebox, cd burners, etc etc). :o
If not... Then you can make a partition in your hard drive installing Linux - If you do this, you will be able to choose which Operating System you want each time you turn on your computer.;)