Overall a Linux based platform can perform most of the tasks equally as well as a proprietary platform using OSS including an excellent preinstalled comprehensive Office Suite called LibreOffice
http://tldp.org/LDP/intro-linux/html/chap_01.html
http://www.libreoffice.org/features/
There is really no reason to use a proprietary platform these days with the exception of High End gaming which will always be the achilles heel of Linux. Otherwise Windows is all but reduntant which is becoming increasingly evident particularly where users upgrading from XP are switching to Linux permanently
Installing Ubuntu as a dual-boot with Windows without partitioning
https://help.ubuntu.com/community/Wubi
I thoroughly recommend the Linux Mint 11 which is based upon Ubuntu 11.04 Its easy to install and easy to use plus it comes with much of the software you are likely to need preinstalled
Linux Mint 11 has a feature called mint4win which is almost identical
Linux Mint 11 Download
http://www.linuxmint.com/edition.php?id=83
Linux Mint 11 Release Notes/User Guide
http://linuxmint.com/rel_katya.php
You download the ISO. image of Linux Mint 11 then you need to create a Bootable LiveCD
https://help.ubuntu.com/community/BurningIsoHowto
Linux Mint 11 can also be run straight from the LiveCD without touching your Hard drive
LUg.