Slaving a PATA drive with a SATA drive

there is no slaving with SATA. you plug the SATA drive, format it and start to move your stuff..

How does windows know which drive to boot to.

don't know about your board, but you may have an option to set the boot priority in BIOS for the HDD. Mine has, so if I plug a new HDD and want to boot from, I just set the BIOS to boot from it..

Do you want to install windows on the new drive?

Yes it has an option to boot to hard disk, but I'm just wondering how it knows what hard disk. I obviously haven't tried this yet, but i will here shortly.

It should have an option to define HDD boot priority too..

Read your motherbaord manual..

The MSI boards don't have an option to boot from "HDD1, HDD2, etc". What you have to do is this: disconnect the old drive from the system. Install the new hard drive and install windows. When windows is done, reconnect the old hard drive. The BIOS will remember which drive has windows on it and boot from it. However, sometimes it won't. In this case, Windows will ask you which copy of Windows you want to boot right after POST. You won't know which drive has which copy of windows until you pick one. After picking one, if the old copy of windows boots, then reboot and pick the 2nd one- which will boot you into the new windows/hard drive. Once that's done, copy the files off the old one in explorer and format it. :-)

If all that still doesn't work (I.E. computer refuses to boot from new drive with old drive installed), buy a USB hard drive enclosure. Boot windows on new drive, connect old drive via USB, copy the files, and format it.

-mpjese