Changing ide hdd to sata on ecs p4vm mobo

Are you talking about removing an IDE hard drive and installing a SATA hard drive in it's place?

Or are you just talking about changing the chipset from "IDE Emulation" mode to "AHCI" mode?

If it's the latter, and if the issue is that Windows won't boot because it has the wrong drivers loaded, then here's what you need to do:

1) Run the Registry Editor (regedit.exe)
2) Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
3) Set the "Start" value to 0 (zero)
4) Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Pciide
5) Set the "Start" value to 0 (zero)
6) Shut down
7) Start up again, but before Windows boots go into the BIOS configuration screens and change the disk mode to "AHCI". Save the new BIOS configuration and restart so that Windows boots.

When Windows starts, it will detect the change, load new disk drivers, and do one more reboot to start up with them.

Hi there,
Your MB takes a 478 CPU, and has 2 IDE controller ports on it, no SATA ports

You may be wanting to take one of the newer SATA HDD's and connect it to one of the IDE ribbons on your computer MB?

If so, what you need is an IDE to SATA adapter, that plugs into the SATA drive, with the IDE ribbon plugging into the adapter.
Makes a SATA drive work from an IDE controller.

Amazon has a couple to choose from, Generic, and Startech IDE to SATA adapter. Cost $8-$20. The HDD will run at the slower IDE transfer rate, but it will work.
IF that's what you are looking for, just be careful to purchase the IDE to SATA adapter, because they also make SATA to IDE adapters connecting an older IDE HDD to a SATA cable.

Good catch!

Ignore everything I said above...