Yes, Linux and Windows can run on the same machine. You would just need to run a dual boot. When you are installing Linux, it will give you the option to partition your harddrive instead of formatting it. Choose this option, and cut a few gigs off of one of your harddrives for linux (around 10 gigs is good, depending on the distro). Run through the install, and when it gives you the option to install a bootloader, choose Grub, you wont regret it
Office XP in Linux: Unless you are using WiNE, no. But there is OpenOffice...
[Edit]: if you need Linux help, come to the IRC room (irc.chattingaway.com and the room name is #linux, a few linux users come and go)
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