Installing in another HDD that has another version of Vista previously installed

I'll try and keep quarry short as I sometimes ramble on.
System had Vista x64.
OS Had problems.
System wanted me to redo my HDD. I didn't want to lose everything on drive. So I took another HDD I had laying around and installed Vista x86. To keep a fresh OS build of Vista x86 I unplugged all of the additional HDD's. I want to re-introduce my HDD's into the x86 OS (9 HDD's) two old HDD have versions of Windows already installed on them. I don't want a dual boot system, but would rather remove the old versions of windows on the drives as I re-introduce them. There is lots of data I want to recover from these old drives. Will I encounted problems when I re-introduce these drives that already have an OS on them?

System is a MCE Library
List of drives.
1. New OS Vista x86 200GB
2. 500GB has a copy of Vista x64 (OS had problems) want to remove OS and keep data
3. 500GB Data only. I wouldn't think re-introducing the data drives would cause a conflict. Is that a correct assumption?
4. 750GB Blank want to RAID0
5. 750GB Blank will RAID with above drive
6. 300GB old version of Windows XP MCE 2005 want to remove Windows and keep data
7. 300GB Data only
8. 300GB Data only
9. 300GB Data only

What files/folders need to be removed from the old drives so system no longer sees an OS? Will this hurt integrity post removal of OS?

Thanks

As long as your VistaX86 drive is Master on Bus1 and the BIOS is set to boot from the drive you shouldnt have any problems the VistaX86 bootloader will not include other Windows Installs only if they where present at the time of installing windows, then delete all the files on the X64 drive just enable "Show all Files" and "Show Protected System Files" remembering to make a backup of anything you want to keep from the Users or Program Files directory.

Yup that's what happened.
When I created the new version of Vista x86 I had all the other HDD's unplugged. So when I started plugging in all the other HDD's the first time it encountered the new drives it asked me to choose an operating system. But there was only one choice. VISTA. So I selected the VISTA and it rebooted. Once back on line it was booted to Vista x86, which is exactly what I wanted. It has never asked me again to select the OS.

Yes in the BIOS the new 200GB x86 HDD is selected as the first choice or Boot drive.

I don't know if the IDE port on my MB (GIGABYTE GA-P35-DS3R INTEL Q6600) would be considered priority or BUS1 as the MB has 8 SATA ports and 1 PATA. I had all the SATA's unplugged and the new Vista x86 was set to Master on the PATA port. Everything appears to be working fine now. Only big job of cleaning up the drives lies ahead. and learning how to initilize the new RAID0 and format it. I'm going to make a new post as I've continually failed to get my new 750GB drives raided.
I've tried all combinations of MBR, GPT partitions and either Basic or Dynamic Disc. all have failed. It must be a setting in the BIOS that I don't have right.
Yes I've created the RAID in BIOS and entered the setup via CTRL + (I)
My prefered RAID is Dynamic and MBR, but it encounters a problem everytime I tell it to initilize.

Thanks for your help, it was much appriciated.
Ralph