Can not load or repair Win 10, USB recovery image doesn't seems to work

[dgvllpnd]

Hello!

I have a Dell Inspiron 15 5578 2-1 with i7-7500U, 8gb RAM DDR4, 1tb HDD, no-cd-tray, no-back-access, with Win10 installed by default.

The problem is that I can boot into my Win 10 partition successfully, but it won't load. After some reboots it automatically starts recovery mode, but it'll also stuck in a black screen with a cursor. This error happened all of a sudden, and with no apparent reason (although I guess that the problem could have started 1 week back when I re-partitioned a FAT32 of 59.47gb to NTFS, but it seems odd)
I have tried using Dell's default installed tool: Support Assist for OS recovery, and it is stuck in an everlasting loading screen, which eventually ends with an error.
I ran the Dell's hardware diagnostic tool available in the Bios and everything shows OK.

The hard drive is an ATA ST1000LM035-1RK1. And it is partitioned like this: being 700gb the Win10 partition, and 160gb the Ubuntu partition.

Ultimately I have tried making a bootable USB with a Win10 image provided by Dell for my system (using rufus in another machine), but it never shows in the boot screen (I have tried in either Legacy and UEFI mode, with either SecureBoot on and off).

I don't know what else to do :/

 

[Colif]

I was glad to see the efi there, I was thinking that might have been the fat32 partition you had altered.

i wonder if this would work. we can try to fix the boot record as I assume that is whats busted here.

start PC, let it try to load windows and hit reset when 1st load screen shows. Try that pattern 3 times and it should load automatic repair
once this finishes and probably fails, it offers advanced options. choose them
this should take you to a blue screen
choose troubleshoot
choose advanced
choose command prompt

We need to use the Bootrec.exe tool. Click on command prompt and type in the following commands, one after the other:
bootrec /RebuildBcd
bootrec /fixMbr
bootrec /fixboot
Exit
Now go ahead and reboot your system. In some cases you may need to run some additional commands.
bootsect /nt60 SYS or bootsect /nt60 ALL

If that doesn't help, repeat the process to get to advanced startup.
there should be a option to Use a device
put USB drive in and choose it from list and PC will boot from it