see also:http://www.metsky.com/archives/134.html 
 

The simplest way:

1.download ThinkPad Intel(R) Matrix Storage Manager

2.extract rar file with 7-zip tools to a folder,eg: c:\temp

3.run the install.cmd file in the c:\temp\DRIVERS\WIN\IMSM\PREPARE 

4. reboot

5. boot to BIOS,Enable ACHI mode.

6.boot to XP