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MBR partition error when reinstalling from 32 bit to 64 bit

Last response: in Windows 7
April 5, 2012 10:59:19 PM

I have just ugraded most parts of my PC including going from 2gb of ram to 8gb. As I am currently running windows 7 home premium 32bit I believe my pc will only be reading 4gb of this ram.

I have downloaded a 64 bit installation iso file & burnt to disk, upon reinstalling I was planning on re-using my current windows product key.

Once past the custom installation option I recieve an error message along the lines of "The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks."

I belive my Hard drive has 2 partions, 1 main area for saving files & program files. It also has a factory image drive.

This is the first time I have built a PC, Is frustrating to have go this far on my own and get seemingly stuck on what is hopefully the last hurdle

(Sorry if this has been posted before, I thought i posted the same question last night but cant seem to find it anywhere..)
a b $ Windows 7
April 6, 2012 12:35:27 AM

well for one thing i dont think you will be able to use your existing product key

and you cant upgrade from 32bit to 64bit

and not sure where you downloaded the 64bit iso--if its a bootleg copy then thats against the forum rules

no piracy allowed here--please read the rules

April 6, 2012 1:31:40 AM

I could be wrong here, please correct me if I am but I dont believe what I'm trying to do do is piracy. If it is am more than happy to go and purchase a copy of windows 64 bit, however that does seem unnecessary as i do have a licenced copy of the 32bit version.

From what I have researched the only way to move from windows 32bit to 64bit is through a clean install/complete reinstall of windows, using the custom install option. I realise this will wipe all current files which I am ok with.

I have a legit copy of Windows 7 and recieved through an upgrade program with HP. The program was in place as I purchased a new PC with Windows Vista a few months before the release of Windows 7. The upgrade disk that was sent to me only had upgrade 32 bit option.

From what I have read the product keys associated with Windows 7 are the same between 32 & 64 bit but different between versions (ie home premium vs proffesional).

Related resources
a b $ Windows 7
April 6, 2012 9:03:34 AM

i meant because you said

"I have just ugraded most parts of my PC"

then your serial key probably wont work--especially if you changed the motherboard

not because of going 32bit to 64bit

try formatting all your partitions--backing up any data first

plenty free partitioning software available if the windows disc wont let you

if the windows disc goes as far as listing your hard drive then use the advanced drive option to format

April 6, 2012 11:10:35 AM

Boot From the Windows Install Disc
The first thing you’ll need to do is boot off the install disc, and then click through until you see the “Repair your computer” link in the lower left-hand corner.
You’ll need to choose the correct installation of Windows and then click the Next button.
And then you’ll get to the System Recovery Options screen, where you can get to the Command Prompt.

Repairing the Master Boot Record
If you want to restore the master boot record, you can simply type in the following command:

bootrec /fixmbr

You can also write a new boot sector onto the system partition with this command (which is often more useful):

bootrec /fixboot

And of course, if you just use bootrec /? you’ll be able to see all the options.
April 12, 2012 5:22:40 AM

Thanks for the feedback, away from home for next few weeks. Will give it a crack when back home and let you kniow how i get on.