Okay, I looked into the BIOS and tried enabling AHCI.
But when I try to start up the computer at the "Starting Windows" animation I get a BSOD and it restarts my computer.
I can't get the error code since the BSOD only flashes for about half a second, but I can see that it is a BSOD.
Putting it back to IDE works fine :s
"When it comes to performance, there really isn't a big difference in using AHCI.
Note: If you installed Windows in IDE mode (which means that you didn't use F6 and supply a driver disk), then simply changing the BIOS setting to AHCI mode and rebooting will cause Windows to fail and will require a repair install. Most people are advising to reinstall Windows if you want AHCI enabled."
This is from Western Digital's own website. But is this really the issue?