how to uninstall windows 8.1 in order to install windows 7

Jumph · 16 Jul 2014

For removing windows 8.1 operating system, and in order to install windows 7..
you can follow most resouces online for removing windows 8 (not 8.1) because the largest diverence is in how to access the correct BIOS options as "the menu options have changed".

While in the BIOS Boot menu, you want to change the "Boot Mode" to "Legacy Support" and change the "Boot Priority" to "Legacy First". This will let you bypas the windows 8.1 hardrive boot, and use the cd-rom windows 7 disk instead. I've spent hours tonight figuring how to remove windows 8.1. This was the solution for me. What a pain MS created with with windows 8.1

Berton · 16 Jul 2014

While in the BIOS Boot menu

But not all BIOSes are the same, different brands implement them as they wish.

My solution to changing to a different OS is to boot to a GPARTED CD, delete all the partitions on the HDD which then gives the desired OS a clean drive for installing. The underlying issue is that one can't simply delete an OS and cannot use an OS it is booted for formatting the HDD, won't allow itself to be killed, which is why a different approach is needed.

If you got the computer with Win7 then upgraded to Win8/8.1 you might be able to use the Factory Restore to go back but be aware that almost anything you do can cause loss of installed programs and your data so be sure to back up your data to an External drive and get your program discs at hand for installation.

Brink · 16 Jul 2014

Some more info to help. :)

Downgrade Windows 8 to Windows 7

gregrocker · 17 Jul 2014

The correct way to uninstall an OS is always to delete its partition after backing up the data.

Every UEFI BIOS firmware has different UEFI, Legacy or CSM settings which require enable/disable or a combination setting to install Win7 on an Win8 machine in a Dual Boot where the drive isn't wiped or to replace Win8.

As pointed out deleting all partitions or wiping the drive is necessary if changing from UEFI GPT format to Legacy MBR, or vice versa. Sometimes it even requires the Convert command as given in Bypass UEFI to Install WIn7.

I haven't yet found a combination of settings that will not allow install of Windows 7, but it can be complicated as when sometimes there is a split Reset BIOS to defaults and Reset BIOS to Win8 Defaults.

Jumph · 18 Jul 2014

Thank you for the responses, it's apparent you guys know more about this I do. I've never replaced an OS before - it took me hours.

Re: deleting partitions, I did this during the windows 7 install. The wizard presented a list of them - think there were like 6 or so, and I deleted all that could (based on some info I saw online - hope that was right). One remained so I assumed that was the correct one to keep.

The machine I replaced the OS for is a lenovo G510 I bought a few weeks ago that came with windows 8.1. So I never upgraded to windows 8, and because using windows 8.1 was the type of experience I wish I could return the computer for, I didn't want any remnants of windows 8 at all.

THanks again

gregrocker · 18 Jul 2014

I have a G500 which I wiped to install Win7, requiring Boot settings of Legacy Mode (to install Win7) and UEFI first since I wanted to try a UEFI install.

Had I wanted to do a Legacy install I would have needed to also Reset to Defaults instead of Reset to Optimized Defaults (Windows 8) which may be the same on your model.

Jumph · 18 Jul 2014

I wish I couldn've taken screenshots, or used my phone for that matter, while I was tinkering with teh windows 8.1 BIOS menu. Given the info I found online - obviuosly I didn't find the right info - but I had to just look at the BIOS menu and options and try to make sense of what to do. It might have actually been a been a case of try this, try again, try this, etc

gregrocker · 18 Jul 2014

I only stumbled across the strange dual "Reset to Defaults" (for Legacy) and "Reset to Optimal Defaults" (for Win8) by accident after trying for a day to install in Legacy mode and giving up to try UEFI instead. Had I changed Boot settings to Legacy Mode and "Legacy First" (instead of "UEFI First") I then needed to Rest to Defaults to get it to install in Legacy mode to an MBR disk. It wouldn't budge without the Defaults reset.

Wilbri · 23 Apr 2015

I became one of the increasing number of crime statistics in the turbulent country when my premises were broken burgled and my very expensive PC and 24" Monitor were stolen together with other removable electronic items last year
As I was not covered by insurance at the time I resorted to returning to my 12 year old XP machine and thus no need to communicate further until now.
A family member has kindly donated an ACER Veriton X270 which is has windows 8.1 installed.
As I am not the registered owner of this software, I need to replace this OS with a copy of my registered Windows 7 professional OS.
From times past all that was necessary was to copy all required documents onto and external drive and then reformat the HDD, but with all the security measures now in place I am a bit concerned that I could have a problem. Yes a new HDD would solve the problem at some expense but I would prefer to find a less costly alternative.
Your advice on this matter is welcomed.

Berton · 23 Apr 2015

Re-establish contact

This was added to a post over 9 months old.

Two things to watch for, one is if the installed version of Windows is 64-bit then the Windows 7 version has to be 64-bit. Same for 32-bit, both have to be the same. If not then a reformating of the HDD to change from 32-bit to 64-bit or 64-bit to 32-bit is required. The other thing is that the Retail version of Windows can be MOVED to a replacement computer. The OEM version cannot be moved, is tied to the computer it is installed on.