有Linux系统下，Windows XP安装盘不能够启动原因及解决方案(ubuntu9.04 windows xp)

原因：
要在当前安装了 Linux 的计算机上安装 Windows XP（假定您要删除 Linux），您必须手动删除 Linux 操作系统所使用的分区。在安装 Windows XP 的过程中，会自动创建与 Windows 兼容的分区。
解决方案（我只介绍我用的方案，带有任何分区工具且可以自启动光盘或U盘，你都可以。参考：http://support.microsoft.com/kb/314458/zh-cn）:
找一个Ubuntu9.04 desktop 光盘自启动， 选择第一个选项：Try Ubuntu without any change to your computer,进入图形界面，选择一个terminal。由于下面操作需要root权限，你可以参考我的上一篇blog：http://blog.csdn.net/dragonfly12/archive/2009/09/30/4620589.aspx
删除分区工具我用fdisk. 下面是我的实际操作：
ubuntu@ubuntu:~$ sudo passwd root
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
ubuntu@ubuntu:~$ su
Password:
root@ubuntu:/home/ubuntu# fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x624aa2e0

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1318 10586803+ c W95 FAT32 (LBA)
/dev/sda2 1319 9729 67561357+ f W95 Ext'd (LBA)
/dev/sda5 3880 6804 23495031 b W95 FAT32
/dev/sda6 1319 1344 208782 83 Linux
/dev/sda7 1345 1466 979933+ 82 Linux swap / Solaris
/dev/sda8 1467 3879 19382391 83 Linux
/dev/sda9 6805 9283 19912536 b W95 FAT32
/dev/sda10 9284 9587 2441848+ 83 Linux
/dev/sda11 9588 9609 176683+ 82 Linux swap / Solaris
/dev/sda12 9610 9729 963868+ 6 FAT16

Partition table entries are not in disk order
root@ubuntu:/home/ubuntu# fdisk /dev/sda
The number of cylinders for this disk is set to 9729.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): d
Partition number (1-12): 6
Command (m for help): d
Partition number (1-12): 6
Command (m for help): d
Partition number (1-12): 6
Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

root@ubuntu:/home/ubuntu# fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x624aa2e0

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1318 10586803+ c W95 FAT32 (LBA)
/dev/sda2 1319 9729 67561357+ f W95 Ext'd (LBA)
/dev/sda5 3880 6804 23495031 b W95 FAT32
/dev/sda6 6805 9283 19912536 b W95 FAT32
/dev/sda7 9284 9587 2441848+ 83 Linux
/dev/sda8 9588 9609 176683+ 82 Linux swap / Solaris
/dev/sda9 9610 9729 963868+ 6 FAT16

root@ubuntu:/home/ubuntu# fdisk /dev/sda

The number of cylinders for this disk is set to 9729.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): d
Partition number (1-9): 7

Command (m for help): d
Partition number (1-8): 7
Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
root@ubuntu:/home/ubuntu# fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x624aa2e0

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1318 10586803+ c W95 FAT32 (LBA)
/dev/sda2 1319 9729 67561357+ f W95 Ext'd (LBA)
/dev/sda5 3880 6804 23495031 b W95 FAT32
/dev/sda6 6805 9283 19912536 b W95 FAT32
/dev/sda7 9610 9729 963868+ 6 FAT16
root@ubuntu:/home/ubuntu#
重启电脑，现在把windows xp安装光盘放入就没有问题了。
至于为什么会这样，是因为硬盘引导分区的问题。这方面资料如果谁有兴趣，可以google上搜去，我就不说了。