Windows – GPT disk error installing Windows 7 64 bit on MacBook Pro 13 mid 2010 with High Sierra

I have spent 4 days now, trying to install Windows7 64 bit on my MacBook Pro 13 mid 2010 with High Sierra installed on it. I had installed in many years ago and it was really easy. I removed it when I replaced my original HDD with 500GB SSD. After many attempts with getting ISO to work with BootCamp assistant, I gave up and tried installing directly from bootable USB by using refind (as pressing opt/alt at start-up did show this USB as a bootable source.

Doing that I get the error "Windows can't be installed in drive 0 partition x (show details)" and the detail gives the error message "The selected disk is of the GPT partition style". Additionally it says that it must be NTFS.

I could click format, but it remains stuck at GPT error.

I tried different solutions so far that did not work.

1. Solution with ExFAT format
   It simply says that format Windows/bootcamp partition to ExFAT from diskutility and restart. Tried it but did not help.

2. solution given with gdisk
   Tried that, but did not help. Still got the message.

3. Solution by using diskpart at the Windows Installation screen. I used it missing to check that it is to be used in case I have separate physical disk. I used it and wiped out my who HDD.

After 3 I started fresh with High Sierra again. But I partitioned my disk before installing any OS. Now, I tried the same to install Windows7, but I get the same message. I realized that above instructions were for Windows 8. Don't know if that makes a difference on how to proceed with this GPT error?

Also in Solution 1, it highlights " make sure that "bootcamp is partition 4". But for me it appears at partition 3. Does that makes a difference?

Output from diskutil

 diskutil list
/dev/disk0 (internal, physical):
   #:      TYPE NAME                            SIZE       IDENTIFIER
   0:      GUID_partition_scheme              *500.1 GB   disk0
   1:       EFI EFI                             209.7 MB   disk0s1
   2:       Apple_APFS Container disk1         409.9 GB   disk0s2
   3:       Microsoft Basic Data BOOTCAMP      89.9 GB    disk0s3

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +409.9 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume MacintoshHD             13.0 GB    disk1s1
   2:                APFS Volume Preboot                 22.2 MB    disk1s2
   3:                APFS Volume Recovery                516.2 MB   disk1s3
   4:                APFS Volume VM                      4.3 GB     disk1s4

Output from gdisk

GPT fdisk (gdisk) version 1.0.4

Warning: Devices opened with shared lock will not have their
partition table automatically reloaded!
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

output from gdisk print partition table

Expert command (? for help): p
Disk /dev/disk0: 976773168 sectors, 465.8 GiB
Sector size (logical): 512 bytes
Disk identifier (GUID): C49B7CD4-E813-445E-BEDB-BCA947F6F707
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 976773134
Partitions will be aligned on 8-sector boundaries
Total free space is 263573 sectors (128.7 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
   2          409640       800991871   381.7 GiB   AF0A  
   3       800993280       976510975   83.7 GiB    0700  

output from gdisk "print protective MBR data

Disk size is 976773168 sectors (465.8 GiB)
MBR disk identifier: 0x00000000
MBR partitions:

Number  Boot  Start Sector   End Sector   Status      Code
   1                     1    976773167   primary     0xEE

Output from gpt -r show /dev/disk0

      start       size  index  contents
          0          1         PMBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6         
         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     409640  800582232      2  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
  800991872       1408         
  800993280  175517696      3  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  976510976     262159         
  976773135         32         Sec GPT table
  976773167          1         Sec GPT header

At this moment Bootcamp is FAT32 partition.

After 4 days of effort, loss of data, I need help. I am not sure if I missed something small to notice after reading page after page.

I came across this solution about converting drive from GPT to hybrid. I would like to try this, but at the same time I notice that almost every article warns about Hybrid GPT/MBR.

I hope there is a simple solution than this or if someone can confirm that this is the only option left to try. I can then try this complicated looking solution as well.