cannot format a GPT partition

[jonboy3]

Hi everyone.
I have made a serious error that i cannot fix. i have a Acer Aspire E1 laptop running windows 8.1, i do not like windows 8 and when my laptop started playing up ( running slow and might have picked up a virus) i decided i would install windows 7 which i like, i got the message windows 7 cannot install on this partition as it is a gpt partition, after reading various forums i deleted the partitions so windows 7 could do its work, that was a huge mistake as it still will not install and i have lost everything to do with windows 8, i backed up my own files but have no tools for windows 8, is there something out there i can use on a usb to reformat the drive so i can install windows 7.
Please help me.
:huh:

 

[usasma]

Normally you'll have to turn off the UEFI and disable SecureBoot in order to get far enough in to format the hard drive.
Haven't done this recently, so I'm unsure if there's an intermediate step (low-level format of the drive).

There is a tool that allows you to install from USB: Microsoft Store

 

[Richman]

Easy Fix to EFI Boot DIsk/Windows Install Issue

I also received the message: "Windows cannot be installed to this disk. The selected disk has an MBR partition table. The EFI systems, Windows can only be installed to GPT disks" many times or similar message.

This is a very common issues many people are having on new systems.

Heart of the issue:
Many newer system BIOS may have an EFI/UEFI BIOS which implies a GPT partition structured HDD. These systems usually have a boot order in the BIOS that has 1st Your DVD drive (possibly stating manufacturers name) as legacy or IDE and 2nd Your same DVD drive in UEFI mode as the second boot device (or visa verse). If your BIOS is set to one mode (EFI/UEFI) and you try and run an install or boot DVD in another mode you will get this error which the system sees as a conflict. Some other forum posts suggest changing your 1st boot device from the one DVD mode type to the other or reversing them. It appears that if your installation media either dvd or usb device is set to boot from one mode and your HDD is already formatted for the other mode or has an existing OS that it was formatted when installing it, this conflict will will produce this error message. Doesn't matter which mode your BIOS is set to by default.

Some tell you to reformat your HDD and switch to legacy bios and reinstall. While this may be necessary if you want to dual boot Windows 7 and 8 together it is not necessary if you are just installing ONE Windows system to a pc and get this message.
While changing the mode in the BIOS may work there may be a more simple method if you can notice or detect the mode switch during the boot sequence.

Simple Fix: Before realizing this I noticed that during the boot process you can, at least on the Biostar I was building, and probably most newer motherboards, see the switch from the one DVD mode type to the other by means of seeing the words "Press any key to boot from DVD" move to another location on the screen or flash a second time in a slightly different location possibly only a few dozen pixels apart making it difficult to decipher. It appears that some systems do some kind of auto detect and switch modes. I simply ignored the first flash of those words and clicked a key to boot from the DVD when I noticed the words flash again a second time in a different location. The Windows 7 then installed as before without problem.

I realized that these words flashing a second time is simply the system switching modes for the installation boot media used for booting.
While entering the BIOS to switch boot modes, it takes extra steps. If you don't notice these words flashing on your screen two times then it may not be switching modes. In this instance it may be necessary to enter the BIOS and manually switch the boot mode of your DVD/USB device.

Consequently, If you are installing a system as Legacy BIOS and not EFI/UEFI then you may at some point want to enter the BOIS and switch modes to Legacy/IDE so that DVD/USB devices boot in the future without error.

 

[Richman]

I know I didn't formulate my first post specifically to your situation so I will try again

Hi everyone.
I have made a serious error that i cannot fix. i have a Acer Aspire E1 laptop running windows 8.1, i do not like windows 8 and when my laptop started playing up ( running slow and might have picked up a virus) i decided i would install windows 7 which i like,

Not sure why you don't like Windows 8, but that is another issue. I for myself actually like it ..... better than Windows 7 since it has a lot better search and indexing and almost decided to switch over but just haven't yet. I guess I can't yet give up on 7 yet on my main rig and seams like when you finally get very used to one OS after 18 months, another come out to switch to. I wish MS had a 3-4 yer plan much like Linux does.

i got the message windows 7 cannot install on this partition as it is a GPT partition, after reading various forums i deleted the partitions so windows 7 could do its work, that was a huge mistake as it still will not install and i have lost everything to do with windows 8,

Out of curiosity, Did your laptop have a 'backup' or 'Recover' partition originally installed by Asus? If so why did you totally delete that? I think in doing so you totally eliminated any possibility of installing Windows 8 on this machine. At least without purchasing a new license unless you can get a backup disk from Asus.
You mentioned 'So Windows 7 could do its work' I am unaware of any work that Widows 7 does that totally removes or reverses a factory installed Windows on an EFI based system other than doing the disk formatting with diskpart wich is only one step that would need to be done.

i backed up my own files but have no tools for windows 8, is there something out there i can use on a usb to reformat the drive so i can install windows 7.
Please help me.
:huh:

I think you would have to (and this is what I have read and have not tried it)
1. Boot into BIOS and remove any EFI boot disk and switch BIOS from EFI to Legacy and change the boot order to DVD, or USB if you have Widows disk on USB
2. Boot to the DVD and choose command prompt to and type diskpart (you will see a load confirmation)
3. Type 'list disk' then 'select disk 0' if there is only one disk.
4. Type 'clean'
5. type 'clean all'

Next you can format for Widows 7 install
6. type 'FORMAT FS=NTFS LABEL="WINDOWS 7"
7. Type 'ACTIVE'
8. Type 'Exit'

You then should be able to load Windows from an install disk but many different hardware manufactures EFI systems seam to have their own set of challenges at times from what I have been reading.