to "delete" one operating system, you best format the partition it was on to a file system supported by the operating system you want use it for from then on.
In your case this means: format the partition you have linux on right now to be of type NTFS.
- Have backups of your data
- apply basic laws of logic
- understand what you are doing (comments)
- double check
Here's what you want to do, step by step:
Disclaimer: Don't blame me for mistakes, I have not done this myself (obviously). Plus, I am only human too.
fdisk -l figure out what partitions you need to get rid of
fdisk /dev/hdx replace with identifier for the hard drive you have linux on
d to delete partitions
? select a number [refer to step 1 for information on what partitions you want deleted]
? repeat as necessary to delete all linux partitions (there should be at least one boot and one swap partition)
n to create a new partition
t to change the partition type of your new partition
x exit and write to disk - THIS STEP WILL DELETE YOUR LINUX PARTITION
Last you need to get rid of grub and have the computer use the windows bootloader again: format the Master Boot Record (MBR) (use DOS fdisk):
The result is the following:
You have an additional Windows NT partition (for Windows XP) which should show up in windows.
Your linux parititions have vanished.
GRUB is gone.