Since I had to look everywhere for how to do this (because everyone assumes that even if you're a complete Linux noob, everyone already has 2-3 years of experience with Linux already!), I'm going to help you out!
This is how I removed a linux partition while keeping my XP partition intact...
First, just go download GParted
. This will save you the problem of navigating though the scary Windows XP recovery disc (where you have to tell it you want to install XP even if you just want to delete a partition). I know I was afraid the whole time that the next time I said OK or continue (while attempting to use the Recovery Disc), it was going to start re-formatting XP before it got to the partition editor.
Anyways, once you download GParted, burn it to a disc using some sort of ISO recorder.
After you have your live boot CD all ready to go, make sure you have a Windows XP recovery disc. If you do, then stick in GParted and delete all of the partitions that Windows XP is not in. Most likely, XP will be labeled as "NTSC" or "Fat32" and the Linux partitions will have a name such as "ext3" or something. After you've right-clicked and selected "delete" for the partitions you do not need, click "Apply" at the top of the window in GParted.
Now, when you restart your computer, you will see something like "Grub>" if you don't put in your Recovery Disc first. This is to be expected, and I'll tell you how to fix it. Start your computer with the recovery disc and when the blue screen finishes loading, press R for the Recovery Console or something similar. It will ask you for your admin password. Usually, it will either be your main account's password or nothing. Try both, and if that doesn't work, then you'll need to download OPHcrack
and burn to disc to crack your own password.
I think it also asks you which version of Windows you want to load before it asks you for your password. I just typed in "1" and it worked! I'm lucky, b/c if I hadn't, I would've had to use another computer to figure it out!
After you enter the correct password, a prompt that looks like "C:\WINDOWS>" will appear. All you have to do is type in "fixmbr". It will give you a warning, but just type in "Y" to go ahead and write the MBR. After it's done, type "exit" and it will reboot your computer automatically. If everything worked out right, there will be no more GRUB bootloader and Windows XP will boot as normal. If you don't want to keep Windows XP as a smaller partition, then I think you can use GParted to make it bigger and fill up the space that was reserved for Linux, but I'm not sure... If you have the disc, try it out yourself!
If you have any problems or if there's any way to make this guide more helpful, please let me know! I'm just a Linux newbie sharing what I've learned! I hope this guide was completely easy to follow, and if it wasn't let me know how I can improve it!