I've had the usb Drives in Plural plugged in including a drive in usb/eSata enclosure as well as the two main storage drives and printer on while each new build has come along and not one issue. So it wouldn't be anything you have had in use for any period of time. I would tend to suspect a glitch while downloading and unpacking the setup files was seen.
If you google windows 10 32% you will bring up a large number of links to problems with Installation problems when the black screen displays 32 % in the circle that indicates the state of the upgrade. Nothing to do with any USB, nor the processes of downloading or unpacking which have completed already - it is installing drivers, and most likely the graphics driver, and has stalled before moving on to installing features.
Not all PCs are created equal. Your issues or non-issues are not the same with other PCs. We are all just trying to help here. Any suggestion is worth a try. And there's no harm in trying.
from Microsoft Confirms Windows 10 Error Causing the Upgrade to Hang at 32%
Although it's mostly a black screen, you can get to see a little of what's going on under the sheets by pressing Shift+F10, and from the command prompt that, opens, run taskmgr.exe to view the details of the processes in operation.
No problems with all that ^^^^ ......FWIW to anybody that doesn't already know a bootable USB flash drive or DVD or mounted Windows Installer ISO is something altogether different as far as Windows ,UEFI or a CMOS BIOS is concerned than all the above . @bad robot & OP a PC aint going to boot off a printer ,normal USB storage drive or flash drive loaded with iTunes or a USB DAC either.
PS if the unusual driver install incompatibility above isn't present maybe the OP should do something smart that usually works in cases like this like a new download and make a DVD if he has an ODD or new USB media U think ....or maybe mount an existing iso for an update install instead if he copied & decrypted the WU esd like he should have & if it ain't corrupted or incomplete .
OTOH Fafhrd might be onto something wouldn't be the first time either thats why I use Google before anything
I had a couple WU install hang persistently at ~ 25 33% and mounting an ISO fixed it, it happened twice on recent test builds with the existing GPU drivers and I wasn't using USB media and at the time on the second one nothing was plugged in ....I never use USB media for booting an installer anyway .
Last edited by blutos cousin; 29 Mar 2016 at 22:02.
Initially for the 10240 last summer running the upgrade over 7 clones and even 7 clean installs the best recommended state the previous version can be in to avoid any type of carry over problems still failed! You couldn't even get to 10% let alone 32$! And it isn't always the video driver at fault either.
This is why having any initial problems seeing 10 go on the option to uncheck the check for updates box is present. That will prevent the 10 installer from downloading anything that could be a problem. I had a good example of that seen here.
For the long time discontinued tv tuner/video capture PCI type 10 automatically found an 8.1 driver and the original software disk being left out of the loop wouldn't allow the last 7 update for the old XP-Vista card go on. The 8.1 drivers and app for the PCI Express version had to be downloaded from the support pages which was also the latest update for a PCIe Media Center form of the card that lacks the RCA composite input jacks for audio as well as video from analog sources. The totally different cards apparently still had the same processor type chip in use apparently.
Windows 10 Insider Preview Build 14295 for PC & Mobile is now live for #WindowsInsiders in the Slow ring
Hopefully we'll be getting a new build dropped soon.