New
#11
Two things
1) it sounds as though you download the combined 32 bit & 64 bit ISO
each bit version of the ISO is only a little over 3 GB
2) You could Download Virtual CD-ROM Control Panel from Official Microsoft Download Center to mount the ISO and run the upgrade directly from that.
I just came across this, so let me know how if it works out for you
3) You could download just the bit depth that matches your current install. If you are trying to change from 32-bit to 64-bit then you'll have to do a clean install afterwards. I'm fairly certain that an upgrade will NOT allow you to change the bit-depth - could be wrong on that as far as Win10 goes though. Lots of new things have been added to many processes.
See if there's anything about that here: Support - Windows 10 Help