Windows 10: Dual boot and shared partition with RO access for only one OS

Hello,

I've been stuck for a while and I'm looking for help.

For a specific usage (...) on a laptop (Integrity protection on an OS partition while another OS is running and hypervisor was not suitable) I had to create several partions on ONE single SSD Drive in order to :
1) Install one OS W10 Pro 1909 (let me call it OS1) encrypted with bitlocker to protect it when OS2 is active
2) Install a second OS W10 Pro (let me call it OS2) also encrypted with bitlocker (even if it was not mandatory)
3) Create a 3rd partition called "data"
I also need OS1 to be able to write on it while OS2 only need to read from it.

What i've tried :
1) use diskpart and set the selected volume on OS2 as readonly... => works fine but booting on OS1 the volume stills as RO (and if i clear the attribute on OS1, it is also cleared for OS2)
2) use diskpart and set the selected volume on OS2 as readonly + add a registry entry (HKLM\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\WriteProtect set to 0) on OS1 to remove the readonly attribute. It fails (stills read only)...

Do you have any idea to set this partition as Read Only only for OS2 ?!!!

=> this is my main need but if you have a tip for that additional problem it would be the icing on the cake : I've tried to set the attributes hidden for the OS1 system volume on OS2... (and wanted to do the reverse on OS1 for OS2), but when it's done I'm unable to have a functional dual boot (on the hidden OS volume)

=> I insist on the point that I'm working at volume/partition level as i only have ONE ssd disk...

thank you in advance for your advice

:)

 

Dual Boot?

I can help here iv had both i used partition magic to split my HDD and i installed vista on one and xp was already on the other only problem is id watch out if i were you for some reason vista does not like to dual boot iv seen this on a couple of my machines and my buddys. so step one have xp installed step 2 find a partitioner of your choice i dont know of any except partition magic and the one included on xp...only thing is i dont think the one on xp will even partition them...then pop in your vista DVD and select the drive of your choice....the only thing i can think of that causes vista to hate dual booting sooo much is that when their are 2 OS's installed xp uses its own prog to list them on boot well vista uses a totally diff boot loader than the previous os's and i think they conflict the problems i hade were the standard missing windows folder missing HAL.dll and the nt one dont remember the name.....that and after your done vista and boot into xp things didnt like to start correctly specially if you scan disk with vista.

 

Dual booting OS

Hi,

I would like to install dual booting windows 10, both OS in same hard disc. I would like to confirm that no issue to have partition C and D in both OS and no access from each other?

Thanks,

Ratna

 

Dual booting OS

I updated previous comment.

And then of course, you have to add the dual boot script on each OS i believe when both are on the same drive.

Control Panel\All Control Panel Items\System>>Advanced settings>>Advanced Tab>>

Settings, change display OS to 5 seconds>>OK

Then Environment Variables>>System Variables>>Edit

Now enter the dual boot script and save

But even if you can see the other OS (AKA) other partition, then because it is an OS, you might not be able to access the other OS/Partition. So you can avoid the other procedures. Unless you wanted access, then you can do as explained.