Q I'm seriously thinking about trying Ubuntu as a dual boot with XP. Is there a way to erase every part of Linux, including undoing partition changes, if I decide that I want to go back to Windows?
A If you want to remove all traces of Linux, there are two main steps: removing the Linux partitions and removing the bootloader. The bootloader should be done first, and the easiest way is to boot from your Windows disc into rescue mode then run fixmbr. This will reset the bootloader back to the Windows one. If you don't have a Windows disc, there are other tools for resetting the bootloader. The Ultimate Boot CD (www.ultimatebootcd.com) contains a couple of these. Download the CD image, burn it to a disc and boot from it. Select Filesystem Tools, then Partition Tools, then MBRtool. Press 4 then 9 to reset the boot code. Alternatively, use MBRwork from the same menu - in this case the option you need is "Install Standard MBR Code" and you should also set the first partition active while you are here.
Once the bootloader is reset, you can use any partition manager to remove the Linux partitions and resize the Windows one to fill the disc. If you have something like Partition Magic on Windows use that, or you can use GParted from the Ubuntu install disc. Boot to the Live CD desktop (the first option on the CD's boot menu), and select Administration > Partition Editor from the System menu. Here you can delete all but your Windows partition and then resize that to fill the disk. Hit the Apply button, wait for it to finish and reboot.