Dell Latitude E6400 blue screen

Hi

I'm having problems with my Dell E6400 laptop recently.. It suddenly freezes then a blue screen comes [I've attached a photo of it]. It happens frequently without doing a specific task.. e.g. sometimes it happens while browsing, playing games.. etc

Also, the WiFi service no more works although it used to work like a week ago, I'm not sure if it has anything to do with the blue screen. The WiFi led turns blue when I switch on the button on the right side of the laptop, but it doesn't do any effect to the windows :/

It's worth to mention that this is associated with XP SP3 windows only, the other windows [Win 7] runs fine. Not to mention that this windows has had a few viruses for the last week [Hope I got rid of them successfully!].. Could this be the reason behind this system failure?

Any ideas on what could cause such a kind of error?

Thanks in advance!

P.S I'm not sure what kind of important information you might need, but I'll be pleased to provide every necessary information that you require.