I completly disagree with your statement. I have personally switched 9 people to Linux of which eight had a hard time just turning on a computer and one was an expert computer user already. I can say they found Linux easier to navigate and install programs. After all how many times have you seen people double click a windows executable only to be flustered by the ensuing next buttons. Seems like a simple concept but is daunting to someone who does not understand a computer. Linux on the other hand is a simple double click, enter your password and wait for it to install concept that people find much easier to do in my opinion. Gone are the days of Linux being a hobby OS that only a few can use but granted some distrobutions are meant to stay that way while most are not. 

...and what percentage of games work with linux? Not being sarcastic, I would like to know.

KohlyKohl, a casual user may find Linux easy, I agree, but I was referring to the gaming part. If all you do is browse the internet, check your e-mail, write up some simple documents, then it's gravy. However, once you get into the realm of specializations, like gaming, encoding, burning, multimedia tools, that's where the problem lies. Gaming isn't as simple as it is with Windows. With Cedega it's not too bad, but there are issues, and you do have to pay for it, since the older CVS' don't cover the newer games. Wine is even worse since a lot of tweaking is required to get things to work, and unless you have the patience and diligence to get a game to work, you won't be playing that game anytime soon.

So, for casual users, I agree it's very suitable for them. For advanced users who do an array of things, it's more challenging so you NEED to know what you're doing and have the patience and knowledge to figure things out on your own and with community support.

More information (as others have already stated)!

Apart from what others have already covered here (antivirus, anti-spyware and DXDiag), you mention "lag" on two games.

Being that two games you mention are online games (I believe), but not on another game (WoW, which is also online), perhaps your problem is related to distance?

As an example, if you are in the US, and are connecting to a European server you will definitely suffer much more lag than if you were connecting to a North American server.

I haven't played the games you mentioned but most online games have some sort of ping or lag counter; whenever possible, pick the one with the lowest number. Apart from that, lag-wise, there isn't much you can do.

Good luck!

 I agree there are times it can be hit or miss but the same happens on Windows as well which caries over to Linux. The great thing about Linux is that it is free and can be installed on the same hard drive as Windows so you do not lose anything if it does not work out. On the other hand if it works out for you security is no longer an issue and that is a big plus.

If you are unwilling to switch for whatever reason I would check for newer drivers for your network card as well as put up a firewall. There are so many factors to lag including your ISP and your OS trying to keep up with the game causing lag and such.