Situation: -New PC, 1 SSD for OS -finally got a new SSD for data, already installed Steam in C
-Uninstalled, reinstalled in D, got stuck in the bootloader.
Couldn't install updates to client, like it would just stop at "Downloading Updates xxxxKB remaining"
So I found some residual files on C, went into safe mode to delete those folders cuz I couldn't in regular mode. (this is happening while I just uninstalled fresh Steam install again)
[SAFE MODE: Windows key + R, then type msconfig > Boot > ✓ Safe boot (Do the same thing after deleting residual files but this time uncheck Safe boot]
Changing DNS to Open (https://use.opendns.com/#win10)
And it has downloaded !!
After downloading update, Steam prompted me to get out of compatibility mode. I was on "compatibility mode" cuz I set the program to run as administrator (one of the possible solutions I tried before the DNS thing).
I undid that and changed the DNS back to stock, now everything works as they should.
Leaving this here to hopefully help you homies someday.