What am I doing wrong? Trying to dual boot Win7 and Win10 with no luck.

[SamuraiInBlack]

As the title says, I'm trying to dual boot the two OSes, no luck.

Upgrading my Win7 partition to 10 resulted in so many crashes and WTFery that I am amazed the recovery to going back to win7 works. Literally, it crashed on the login screen and ate my primary account/profile but kept my wife's, and also crashed just trying to load the desktop. So I undid that upgrade out of necessity.

I'm using my free install to do a separate install of Win10. I'm using it on a flash drive. Win10 freaks out because the SSD isn't for GPT, which, if I am understanding correctly, means it's a UEFI thing. My SSD is formatted for MBR, so that means it's done the old way, and Windows 10 won't install because of that.

So I made a Win7 backup image, wiped the SSD clean, tried again and Win10 doesn't see the drive. Bit of a headscratcher there for me. I redo the drive for GPT, even format it, and it still doesn't see it. Commence arm flailing and a colorful array of words. I've done the settings for UEFI on my board, I've done the Legacy+UEFI, I've done just about every combination I can think of to make this happen and it isn't.

Is all this headache coming from me not installing Win10 from the DVD drive on a burned ISO? Because that is the only thing I have not tried yet and I'm not about to waste money on a stack of burnable DVD's just to find out that doesn't work either.

FYI yes I have a key. It lets me use my Win7 key for the clean install.

 

[Deleted member 245375]

Well, the biggest immediate issue is you're not supposed to use the Windows 7 key or installation anymore if you're using the Windows 7 Product Key to get the free upgrade offer to Windows 10 in the first place. Now, that's probably not why this is happening (your issues) but even so, technically once you serve up that Windows 7 Product Key to get Windows 10 that Windows 7 license is invalidated after 30 days but as stated in other posts in other threads Microsoft basically doesn't give a shit at this point. That might change, however, in the near or long term future where they could technically lock things down and refuse to provide any updates whatsoever (and I mean absolutely nothing) for users with Windows 7 installations that are still used actively after they took advantage of the free upgrade to Windows 10.

I'm not saying you can't do this, I'm just saying you (and we, and me, also) aren't supposed to. It's up to you to do things the way you want, obviously.

It's their OS, not yours/mine, they can do whatever they want with it and there's nothing the end user can really say or do about it especially if they're breaking the licensing terms which is exactly what that would be doing. You get use of one OS or the other, but not both is the general idea at work here, and definitely not at the same time.

Having said that, GPT just means it allows for partitions larger than 2TB iirc (I don't use GPT with Windows, only with OSX) and I doubt you've got an SSD larger than 2TB (but you might, you didn't specify). Windows 7 does not like GPT - it is capable of using it but it really doesn't like it and I'm not going to get into a big explanation (yes, me, I said that, a person that usually writes guides thousands of words long in the blink of an eye) as to why it doesn't like it or how to actually get it functional with a GPT partition scheme.

As for using an actual optical disc, it shouldn't matter at all. Try this:

- clean install Windows 7 on the drive of choice (disconnect every other drive in the system if you have more than one, and I mean all of them, totally disconnect them completely and only have the one drive you intend to use for Windows 7 and Windows 10 in a dual boot situation), remove all the partitions during the installation, choose the size of your Windows 7 partition (it will create two - the System Reserved one which is 100MB in size and then another one depending on the choice of size you have for Windows 7). LEAVE THE REST OF THE DRIVE SPACE UNALLOCATED - this is crucial at this point, just don't create another partition, don't format that space, etc, leave it totally unallocated.

- when you have Windows 7 up and functional, then go and install Windows 10 and point it towards the unallocated space. Don't change anything else (unless you must based on the amount of free space left after the Windows 7 installation), just point it to that unallocated space and click Next so it handles the partitioning/formatting.

This should work fine for your situation, if it doesn't for whatever reason then I'm not sure what else to suggest. I'm suspecting that you do have multiple physical drives of whatever kind in the same machine all attached and functioning and the installer for Windows 10 is kinda getting confused (lame term I know but it's a proper way to describe it) with the partitioning scheme of the drives. Whenever you do an installation of an OS I highly recommend you always always disconnect every drive that isn't relevant to the actual installation meaning anything that's not the target installation drive and when everything is finished and working THEN you reattach the other drives and re-assign drive letters using Disk Management as required if actually needed.

Personally I'd say move the ISO contents to a USB stick to save time but, I still use optical media myself without any issues, got a nice external USB optical drive that works just fine when needed but I do prefer to use USB sticks aka Flash drives and USB thumbdrives and many other names for such purposes. While I know USB 3.0 drives are even faster I prefer to just use USB 2.0 drives which are nearly universally supported without any issues; sometimes USB 3.0 drives won't be recognized or working properly without the necessary drivers and it can make getting the OS installed (to make use of the drivers, oddly enough) much more difficult. With pure USB 2.0 sticks, it's never an issue, ever.

Good luck.