Good news is that you have 1 PICe 16x available. The bad news is that I have no idea if Pentium 4 and 1 gig are able to support Portal and LoL. On the other hand, if those are enough, then you can just buy a card for sub 100 to play those two specific games and you'd be good. The bad news to that is that you might need a better power supply, since the specs dont say what it is you have we can't say if it will be enough or not.
Tag(thx fkusumot) - "Yet again I completely fail to see your point..."
HD vs Wii, PC vs HD: http://www.vgchartz.com/forum/thread.php?id=93374
Why Regenerating Health is a crap game mechanic: http://gamrconnect.vgchartz.com/post.php?id=3986420
gamrReview's broken review scores: http://gamrconnect.vgchartz.com/post.php?id=4170835
