Insider Build Install messed up drive letters - Microsoft Community

have multi-boot system: xp pro x64 w/sp2, windows 7 ultimate w/sp1 v6.01 build 7601.23807, windows 10 pro v1703 build 15063.447 (upgraded 8.1), , windows 10 pro v1703 insider preview build 16232.1000.

computer setup has 2 hard drives divided 4 partitions each, follows:

disk 1: primary partition = c:\, extended partition/logical drives = e:\, f:\, g:\.
disk 2: primary partition = d:\, extended partition/logical drives = h:\, i:\, j:\.

labels these partitions (as shown in win7 w/sp1 , win10 (upgrade 8.1) > admin tools > computer management > disk management):

name 01 - c:\ - boot
name 02 - d:\ - win10 insider 64
name 03 - e:\ - media stuff
name 04 - f:\ - originals
name 05 - g:\ - slipstreaming
name 06 - h:\ - win 7 w/sp1
name 07 - i:\ - win 10 update 8.1
name 08 - j:\ - xp pro x64 w/sp2

my original problem posted her: https://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_install/fails-to-update-16226-to-16232/fb2c16fa-794a-4df1-811a-ff0a1664ff7a

having no recommended solution used build 16193 iso burn dvd. reformatted "d:\win10 insider 64" , rebooted computer. system booted dvd , selected custom install "d:\win10 insider 64". there no installation problems drive problems noticed. allowed windows update download , install insider preview build 16232.1000, installed no problems noted.

the drive problems noticed custom install resulted in drives letters being changed, follows:

name 01 - d:\ - boot
name 02 - c:\ - win10 insider 64
name 03 - g:\ - media stuff
name 04 - h:\ - originals
name 05 - i:\ - slipstreaming
name 06 - j:\ - win7 w/sp1
name 07 - k:\ - win 10 update 8.1
name 08 - l:\ - xp pro x64 w/sp2

what happened letters e:\ , f:\ , why?

i did online search , found website: https://www.tenforums.com/tutorials/79064-change-assign-drive-letter-windows-10-a.html

the web site above has 4 options.

i scrolled down option 4 , found 'to change drive letter in registry editor' , read procedure - this, me, seems make sense want change drive letters drives listed in win10 insider preview - not other operating systems. concluded changing insider preview's c:\ d:\ , d:\ c:\ not idea because of installed software , installed location - more system not boot insider preview either.

or, know how custom install drive/partition of user's choice without install routine arbitrarily changing drive letters?

correct, switched dvd & storage partition. used disk management ( ms partition tool) , swapped drive letters , hard reboot registry update itself.

Windows Insider Program / Windows Insider Preview / Install, upgrade, and activate / PC