How to convert system disk Win7-64 into GPT?

[GiovanniG]

Hi all and thank you for support!
I'm maintenaincing a videosurveillance server, where Win7-64 is installed. Previously it hosted a system disk 2TB and a storage disk 4TB. The system disk 2TB begun losing sectors so I needed to replace it, and since the client would add some cameras in future, I bought a 3TB drive.

After cloning disk I can't use all its capacity (I can't have the exeded partition bigger then 2TB) and I can't convert it into GPT (I suppose because it is in use). There are the first partition of 100MB (boot), the Windows partition (around 70GB) then the rest was used as an extended partition to store camera's records.. I need to expand it at maximum disk capacity.

Does Win7 boot on a GPT disk? (I suppose natively it didn't, but maybe now they introduced the support after updates):
With which utility can I convert the disk?
When I convert, will I lose all the partitions? Should I backup (Ghost) the partitions and restore them later? Thank you a lot!

 

[Barman58]

The issue of conversion to GPT from MBR is complicated by the fact that you will need to have hardware that supports EUFI which is a replacement for the older BIOS., You also need a 64 bit OS which is OK by your specs

Boot Windows 7/8 from GPT on BIOS system : No hybrid MBRs or DUET! shows several options for the installation of the system unde EUFI and GPT.

You should fully backup your existing drives (disconnect the 4TB data drive during install and conversion ), Images taken with something like Macrium Reflect should be sufficient and you can then either clear and reformat the drive using windows (difficult for the system drive ), or use the free MiniTool Partition Wizard | Best partition magic alternative for Windows PC and Server software to convert the existing partitions and then clone to the new GPT drive ( backups are still essential )

What I would do in your position is to add a small SSD to act as a system drive which can be formatted MBR and use your existing hardware and then format the two other drives with GPT to utilise all the drive for data, thus totally removing the boot issue

 

[GiovanniG]

Thank you for your kind help
Honestly I would not ask client to pay more to buy an ssd just for boot issue, I would try to boot windows directly from the gpt drive. I have a Asusrock pro 3 mobo with latest BIOS, the drives are already configured in uefi. I would ask some questions:
It's ok to backup with ghost32 12.0 under mini Windows XP or Windows windows 10 64bit and restore later the image with the same Ghost? Or should I use Macrium reflect?
After backup, it's enough to destroy, set gpt and rebuild partition using best partition magic alternative? Or better to boot under miniwin10 64, use diskpart to clean drive, set to gpt, build the 100mb partition(need to reboot here?), set active and install boot, and then replace with ghost the partitions? The 100mb boot partition and the windows one? Would kindly ask briefly the step by step procedure
thank you a lot!

 

[GiovanniG]

I'm kindly ask for your support, thank you!

 

[Barman58]

Your backups can be performed with what ever you are comfortable using, Indeed this is always a good idea as you can concentrate on the task not the software.

As for the actual conversion, as you already have the drive set-up, I would try using the Partition Wizard software to convert the file system - if this works then you are good to go

if not you can clear the disk set to UEFI/GPT and then either install or recover the software from your backups. How and when you set the partitions and sizes is up to you in this option you can do it before or during installation or during recovery as is your wish.

(One thing to add here is if there is a likelihood of upgrading the system to Windows 8.1 or Windows 10 in the future you may want to set the system reserved partition to 500MB to allow for this).

The actual procedural step by step is in the link I provided in my first post - You may want to make a print copy of the details before you start

 

[samuria]

There are software that can change it without reformatting or loosing data may be worth a try

 

[AddRAM]

As Nigel has said Partition Wizard will do it, I personally have never converted an OS disk, only data disks and that went fine.

 

[Barman58]

I have converted system disks successfully , however I use the pro (paid) version of Partition Wizard, and I think they may have removed the conversion ability from the free version. If so then the only way to proceed would be to backup the data (ghost or Macrium as preferred), clear the drive - convert drives using Windows/ Dos commands and then restore or re-install the system and data as needed

 

[samuria]

gptgen should do it Convert MBR to GPT Disk without data loss in Windows 10

 

[GiovanniG]

Thank you a lot mates about help!
I'll try gtpgen and post you the result

 

[AddRAM]

But if he tries to convert it, wouldn`t he have to change the Bios to UEFI, as it`s probably in Legacy mode now.

And wouldn`t he have to have the other 2 UEFI partitions along with the hidden partition for the the OS to boot ?