Windows 10 is Stuck in Spinning Dots

Hi guys, I need some help. I just encountered this bizarre problem on Windows 10 64-bit (this is the second time that I encountered the problem this year).

Here’s how the problem started:

1. I noticed that Windows 10 Pro 64-bit is stuck on spinning dots. I’ve waited for more than 2 hours just to see if it is going to load Windows but it isn’t, I tried to continue waiting but the dots just keep on spinning the whole morning.

2. I tried to enter WinRE (Windows Recovery Environment) by way of holding the power button for 10 seconds three times in a row but it got stuck in “Attempting repairs” screen.

3. I tried to force it to boot in Safe Mode by issuing the command “bcdedit /set {default} safeboot minimal” in Command Prompt so that I could disable “fast star-up” in Control Panel by way of its Windows DVD installation media but it is not working.

4. I tried to scan the drive using CHKDSK /F /R but it found NO ERROR in both partitions (C and D).

5. I booted again using its Windows DVD installation media, when I click Drive C: it says that I cannot install Windows in it because its partition style is MBR.

6. I successfully reformatted Drive C that but it still does not allow me to install Windows in it because its partition style was MBR.

7. I deleted the Drive C partition but it does not allow me to recreate the partition because its partition style was MBR.

8. What I did next is I also deleted the Drive D partition, at this moment there’s no partition existing on the hard drive. When I tried to create a new partition, boom, I successfully created two partitions on the drive (C and D), the drive is now GPT.

9. Then I was able to install Windows 10 and the machine is running again with no problem for two days now.

Note: I’ve gone through all those steps because I do not want to do a reinstall or reformat the machine because a payroll program is installed in it. But it got me no choice but to do a reformat instead.

Additional info: When I first encountered this problem I also did all the steps that I mentioned above the only difference is that I tried to write a new boot sector and fix the MBR using the commands fixboot and fixmbr respectively but it does not fix the problem I also ended up deleting all the partitions on the drive (the machine is now running for more than 6 months now without a problem).

My questions are:

1. What is the cause of the problem? Could it possibly be that “fast start-up” feature is messing or conflicting with some drivers or software at start-up?
2. How to troubleshoot it? (I was not able to turn-off fast “start-up” because I was not able to make Windows start in Safe Mode).
3. Why is the Windows 10 DVD installation media won’t allow me to re-create the partition that I deleted saying that the disk partition style is MBR? I have to delete all the existing partitions before I can create new partitions on the drive (the drive is now GPT).

I would also check drive's health with Hard Disk Sentinel and/or a program from HDD's maker.