i am having problem with multiple operating system. i computer configuration is :

motherboard: ASUS P5S-MXSE
RAM: 1GB
Hard Disk: Samsung Sata (80 GB)

now i am trying use 2 operating system. (windows xp and Redhat linux Server 5). In my BIOS there are 3 IDE configuration (IDE, RAID and AHCI).
i installed windows xp using the IDE configuration. when i tried to install the RH5 in IDE configuration the installation cd didn't detect the hard drive. then i tied the RAID mode. i also didn't work. then i tried in the AHCI mode. then the installation cd found the hard drive. so i installed the RH5 in the AHCI mode. now the problem is i cannot boot neither windows nor the RH5 in the same mode (IDE or AHCI). every time i want to use a operating system i have to go the BIOS and change the configuration mode. its really painful and i guess harmful for my pc. so i am looking forward for a solution. please help me out !

I'm not understanding "IDE configuration" when you say the disk is SATA.

If you are not tied to RedHat Server for some reason, I would simply try a different distro. If you like RedHat, take a look at Fedora.

This article may help you, it gives a step by step to enable both distros with AHCI enabled

http://forums.pcper.com/showthread.php?t=444831

Larry webb,
it didn,t work. your solution will only work for the Intel chip set. i already mentioned i am using ASUS P5S-MXSE, which has a configuration of:

- LGA775 socket for Intel® Core™2 Duo/Pentium D/Pentium 4/Celeron
- SIS 671FX+SIS 968
- FSB 1066/800/533MHz
- Single-channel DDR2 667/533
- SIS Mirage 3 Integrated Graphics
- 2x SATA 3Gb/s with Raid 0, 1 funtion
- Gb LAN

so its actually using the SIS chip set. Can you give me the same solution for SIS chip set?

Here is numerous articles addressing your problem

http://www.google.com/linux?hl=en&q=...ci&btnG=Search