my gf has a mac and its her 3x getting it fixed the first two times was from VIRUS yes macs can get them! and i didnt even pay half as much for my HP
That's probably a function of the owner, not the hardware. You don't blame the car when the driving sucks. I never got viruses on my PC's. Besides, if there's malware for your mac, you have to physically type in your password to allow it to install. #1 cause of malware/virus installation on a mac is user error.
Anyway, I use a Mac...then again I do photography/video editing. Never had a problem with my macs. I remember my old Compaq laptop overheated in the middle of class once...and so I stormed into the bookstore and the iBook had a really good rebate on it ($800), so I just bought it then and there. I was impressed enough to get more mac hardware.
Don't get me wrong, I'm no computer idiot (My desktop is self-built), and I knew how to tinker "under the hood" so-to-speak with my windows machine...it's just nice not really having to do that. Now, when I use my friends' PC's, it's like night and day. You miss little things like two-fingered scrolling/image manipulation via the trackpad, spaces/expose, and CMD + shift + 4 to selected screenshot vs. the cumbersome "print screen, CTRL+C, open image software, CTRL+V, save" method on a PC (unless there's an easier way I don't know about)
For the OP...either one is fine, you can boot into XP with a mac no problem (I use VMware fusion...once in a blue moon). I've never had any compatibility issues with docs (I run MS Office). BUT, if you're on a budget... pick up a Lenovo or other good quality PC laptop, it should last you the 3 years of classroom instruction.
EDIT: actually, i think lenovo's are just as expensive as macs for the same hardware/software set up...at least the good ones are.