Windows 10 + XP Dual Boot Problems - Only booting XP

Hello! After a lot of other problems of mine with SATA drivers and Windows errors, I have managed to boot again Windows XP after installing by rebuilding the bootconfig in the recovery console.
Now I have made EasyBCD to work and I have errors similar to this thread (Windows 7 + XP dual boot problems - Boot possibile only from XP).
When I try to add the Windows XP entry it gives me the message "An error occured while attempting the specified create operation. Insufficient system resources exist to complete the requested service.", after writing the MBR with the Vista+ BCD/bootmgr bootloader, but I haven't rebooted yet and I am too afraid thinking the win 10 won't work and XP not showing.
I'm doing this on a Dell Latitude E6410 laptop with i5 520M, 4GB RAM and 500 GB HDD.
I'm also confused about the partition as it shows in Diskpart:
Partition 1 - Primary - 500 MB - 1024 KB (System Reserved, hidden in Win 10 but not XP)
Partition 2 - Primary - 97 GB - 501 MB (Win 10 installation)
Partition 3 - Primary - 348 GB - 98 GB (All of my files, shrinked this partition to create the XP one)
Partition 4 - Extended - 20 GB - 446 GB (I thought this was the XP installation as I was trying to edit the boot.ini with this one from a linux bootable drive but)
Partition 5 - Logical - 20 GB - 446 GB (I think this is the XP installation but I have no idea what's with the 4th Extended one)
Thank you.