Long BIOS pause on SATA screen when booting

I have an XPS 410. Recently the BIOS pauses for about 30 seconds on the SATA screen when booting.

I found that if I switch SATA to ATA emulation then there is no pause but Vista won't boot.

When I look at the boot sequence in the BIOS it shows the SATA hard drive as 'not present'. It does not show that for the CD-ROM which is also SATA. I also noticed that if I put a bootable CD-ROM in the drive, it will boot even though that is only second in the boot sequence after the hard drive.

 

Can you provide a link to a .PDF of your system manual?

 

http://support.dell.com/support/edocs/systems/dim9200/en/index.htm

 

Vista was pre-installed and it would have used the SATA driver. When I put it in ATA mode, then I guess Vista can't find that driver.

 

I remembered something that may be relevant. I installed XP for dual-booting. The XP install disk does not have SATA drivers. The XP install stopped with an error and a hard boot was required to recover. That is when the BIOS pause first appeared. But it went back to normal on subsequent boots.

I tried several different things to get XP installed the way I wanted. So I had a bunch of hard reboots. Each time I would get the pause which then went away. At some point though, it did not go away.

I would love to know what caused this strange behavior pf a pause that went away on the next boot.