MBR and GPT woes

[sorcerer]

A mate's wife recently got caught out by the phone call, "I'm from Microsoft and your computer has been hijacked by people traffickers and/or got a gazillion faults" scam. She managed to stop payment just in time but they had access to the machine so my mate wants a nuke and pave to be on the safe side because he's terrified of what they may have left behind.

The machine is/was quite happily working and continuing to run Windows 7 Home Premium SP1 and the drive was split into two partitions, a system and a data partition, with things like the Documents, Pictures and Music folders residing on D:.

I forgot to pick up his Windows 7 disc when I went round there earlier so I used Nirsoft's ProduKey to recover his Windows product key then booted from my Win 7 iso on my Zalman, deleted the existing C: partition and attempted to create a new partition in the now unallocated space, only to be confronted by the following message:

Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks.

But Windows WAS installed to that disk (537 days ago actually) and working perfectly well up to half an hour ago when I started work on it. As mentioned earlier, the D: drive still has all his documents, music and photos on it, so what's happening here and what can I do about it?

 

[Porthos]

I used Nirsoft's ProduKey to recover his Windows product key

Might not work for activation. Make sure you have a readable COA

the D: drive still has all his documents, music and photos on it,

Just back it up to an external

what can I do about it?

And format the entire drive and stop fighting it.

 

[Larry Sabo]

Why not just convert the MBR to GPT then try the install again? I'd image the "D" partition first, just in case.

 

[sorcerer]

Thanks for your suggestions guys and yes, I could/will do either of them as the quickest fix, but I'm also trying to understand how something like this happens. How can something that's been working and running well for over 500 days suddenly think that there's been such a huge change that it refuses to put Windows where it was just 30 minutes previously?

 

[sorcerer]

It's a machine that I built for him myself. It uses an MSI motherboard and I bought all the components, including the 1TB Western Digital drive and the Windows 7 DVD from Ebuyer. Having installed Windows on it myself from scratch I know it was an MBR disk and that everything has been running perfectly in the 537 days since I handed it over to him, so I'm still left wondering what's going on.

Oh, and neither of them want anything to do with Windows 10. They both like, and are completely intent on sticking with, Windows 7. - already tried to convince them but to no avail

 

[sorcerer]

When I first built the machine I knew they wanted Windows 7 so no need for 'secure boot' or UEFI stuff and I set it to the only other option which is Legacy+UEFI. I knew it was like that but, once you planted the seed of doubt in my mind I went in to check and found that it was indeed still the same.

However, after exiting BIOS it is now working as it should and is happily installing Windows 7 on its MBR disk. I absolutely promise and swear to you that it was already on Legacy and I made no changes whatsoever, so what the hell is that all about??

Thank you 'Computer Bloke' for planting that seed of doubt and making me look but I am now more convinced than ever that I hate computers!

 

[mr m]

Porthos has the answer. You must wipe out all existing partitions and then reformat. Don't forget the small System Partition that Win 7 creates.

I've also read that changing the DVD boot order to non UEFI worked for some users.

 

[sorcerer]

Porthos has the answer. You must wipe out all existing partitions and then reformat. Don't forget the small System Partition that Win 7 creates.

I've also read that changing the DVD boot order to non UEFI worked for some users.

I don't actually know what the problem was mr m, but thankfully I didn't need to wipe everything out and now Windows 7 is back up and running, and all updated too. Very weird, but it seems that the very act of just going into the BIOS and coming out again without making any changes whatsoever was enough to get it past this little hiccup. It always was, and still is, an MBR disk so why it temporarily thought otherwise is beyond me. Cheers anyway my friend and thanks for your reply.