首先是安装，安装其实不难，但是因为我第一次加载xp的ISO镜像的时候出错，以为是安装的问题，结果删除了一次，最后找到问题所在才明白，不是安装的问题。

安装vbox先安装一个“dkms”，它是一个叫做动态核心模块技术，可以Google了解一下。安装它要有rpmforge源，直接yum安装就可以

[root@ienter ienter]# yum install dkms
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
 * base: mirrors.btte.net
 * extras: mirrors.btte.net
 * rpmforge: repoforge.eecs.wsu.edu
 * updates: mirrors.btte.net
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package dkms.noarch 0:2.1.1.2-1.el6.rf will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package      Arch           Version                     Repository        Size
================================================================================
Installing:
 dkms         noarch         2.1.1.2-1.el6.rf            rpmforge          69 k

Transaction Summary
================================================================================
Install       1 Package(s)

Total download size: 69 k
Installed size: 232 k
Is this ok [y/N]: y
Downloading Packages:
dkms-2.1.1.2-1.el6.rf.noarch.rpm                         |  69 kB     00:01
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : dkms-2.1.1.2-1.el6.rf.noarch                                 1/1
  Verifying  : dkms-2.1.1.2-1.el6.rf.noarch                                 1/1 

Installed:
  dkms.noarch 0:2.1.1.2-1.el6.rf                                                

Complete!

ok，然后我们下载vbox，下载地址在：https://www.virtualbox.org/wiki/Linux_Downloads，直接下载CentOS6版本的就可以，然后rpm安装

[root@ienter vbox]# rpm -ivh Vir*
warning: VirtualBox-4.2-4.2.16_86992_el6-1.i686.rpm: Header V4 DSA/SHA1 Signature, key ID 98ab5139: NOKEY
Preparing...                ########################################### [100%]
   1:VirtualBox-4.2         ########################################### [100%]

Creating group 'vboxusers'. VM users must be member of that group!

No precompiled module for this kernel found -- trying to build one. Messages
emitted during module compilation will be logged to /var/log/vbox-install.log.

Stopping VirtualBox kernel modules [确定]
Uninstalling old VirtualBox DKMS kernel modules [确定]
Trying to register the VirtualBox kernel modules using DKMS [确定]
Starting VirtualBox kernel modules [确定]

这样我们就安装成功了，可以直接新建一个虚拟xp，这个不多说了。

但是我在加载xp的ISO镜像的时候抒错

报的是“Could not get the storage format of the medium”，镜像是MSDN的，没有问题，因为我工作电脑就是用它安装的，最后终于在官方论坛找到了问题答案，有位网友是这样描述的：

As for the ISO, this error comes up when the file does not meet the standard specifications. This includes file size. I remember something that it needs a multiple of 4 to be considered a correct ISO. If the ISO ends with 512 bytes, it will fail the specification check.

看来是格式不符合标准，最后是在另一电脑上安装UltraISO，在它的“工具”中有个“格式转换”，选择这个ISO镜像，设定好输出目录，还有就是输出格式，这个设置为“标准ISO”，点击转换就可以了，很快，两分钟的事情，转换后我看了看文件属性，是变了一点，不多，几M的样子。然后再在vbox里加载，ok，可以正常安装了。