Upgrading Win 7 that is freshly installed on an external USB 2.0 HDD

Hello,

I have just installed a fresh copy of Windows 7 Pro (x64) onto an external hard drive (connected via USB 2.0). (I used a freeware program called WinToUSB to achieve this.) It now exists alongside my normal Windows 7 installation (which is on an internal SSD). My goal is to upgrade the external copy to Windows 10 without having it alter the way my PC boots normally when the external HDD is powered off.

Currently, I can switch between the two copies of Windows 7 by choosing the boot device from my mobo or just by turning on the PC with one of the drives disconnected. My hope is to keep it this way (in a "kind of, but not really, dual-booting" scenario).

My plan is to run the Windows 10 upgrade on the external Windows 7 while my internal SSD is unplugged from the mobo (an Asus "P8Z77-I Deluxe/WD").

Will this work as I expect it to? My hope is that there will be little to no evidence of Windows 10's existence when I turn my PC on while the external drive is disconnected (or powered off). Will Windows 10 affect my mobo's UEFI BIOS or anything like that? Basically, my fear is that Windows 10 will somehow insert itself into the mobo or somehow lock me out of booting normally from my SSD. (All I really want to do is test out Windows 10 for a while before I upgrade my normal Windows 7 install.)

Thanks!

Do you have two separate licenses for Windows 7?

Yes. Both copies are unique, activated, copies of Windows 7. (My laptop died on me recently and I was able to use the Windows 7 Pro key I had on there on this latest install.)

I don't know if Windows 10 will upgrade on a removable drive. What I would do is copy the Windows 10 ISO file to the removable drive. As you said, disconnect the SSD and boot into Windows 7 on the removable drive, mount the ISO file with a program such as UltraISO and run setup.exe from the mounted virtual drive. If it upgrades, it won't do anything to the Windows 7 on the SSD or the UEFI bios.

My bet is, though, that you are going to get an error in Windows 10 that says it can't upgrade on a removable drive.

Okay, thanks for the info. I'll give it shot.

Ran the setup from a mounted ISO as you suggested and it worked very well! Windows 10 is running perfectly (albeit a bit slowly given the USB 2.0 connection) from the external HDD. Thanks for the help.

Also maybe worth nothing: It seems that Windows 10 defaulted to zero paging file (maybe since it detected a low hard drive speed). Is it recommended to keep it this way?

sarge117 said:

Ran the setup from a mounted ISO as you suggested and it worked very well! Windows 10 is running perfectly (albeit a bit slowly given the USB 2.0 connection) from the external HDD. Thanks for the help.

Also maybe worth nothing: It seems that Windows 10 defaulted to zero paging file (maybe since it detected a low hard drive speed). Is it recommended to keep it this way?

Depends on how much RAM you have. I have 32 GB and no paging file. You can always let it run for a while, if you don't do absolutely critical work, and see if you get any out of memory errors. Turn on a paging file if you do.

sarge117 said:

Ran the setup from a mounted ISO as you suggested and it worked very well! Windows 10 is running perfectly (albeit a bit slowly given the USB 2.0 connection) from the external HDD. Thanks for the help.

Also maybe worth nothing: It seems that Windows 10 defaulted to zero paging file (maybe since it detected a low hard drive speed). Is it recommended to keep it this way?

Very surprised to hear this! In effect you have created a Win10 ToGo upgrade install from Win7 ToGo (before that term was invented).

In other threads I have been asking about how to update a Win10 RTM ToGo install up to TH2 1511 using an in-place upgrade install (i.e. what you just did, except you started from Win7 rather than Win10 RTM). It always fails; I have tried everything I can think of, and in the end it all boils down to the same error message: "You Can't Install Windows To a USB Drive Using Setup".