Computer refuses to boot after failed system image creation

[cpugeek21]

I was trying to create a system image for the very first time yesterday, but my computer went into sleep mode after a period of inactivity and then it refused to come out from sleep mode. 

I then tried to force restart but now it does not even read the boot drive. Even when I unplug all the drives other than my boot drive, and go to BIOS and set the boot drive, it still reads "Boot device not detected".

So, I tried a couple of options but failed, such as using another computer to create recovery media. However, when I try to recover previous system images or troubleshoot, there is always an error. There are also no system images to be found. I also tried downloading Ubuntu and accessing the drive from there but the process gave me errors as well.

So here is my question. Since the computer is self-built, I wouldn't mind doing a fresh reinstall of windows as long as I can get the data out of the drive as far as possible. I'm trying to mitigate the damage as much as possible so I have thought of a couple of solutions, as well as some answers I might have regarding the data on the drive.

1) Is the data on the drive still present? i.e when the system recovery failed, did the entire drive get wiped out or could there just be some sectors that got messed up and hence the boot drive is not detected? I know this sounds like a stupid question, as no one can answer that but myself, but since I cannot boot into windows, there is no way I can see the space occupied on the drive.

2) Kind of related to the first question. If the data on the drive is likely still present, can I just go and buy one of those usb ssd hot swap bays and try to pull out all the data, then do a clean reinstall of windows? I could buy one, since they aren't too expensive but I would hope that I can solve this issue without spending any money.

If the method above doesn't work, I have also thought of downloading a fresh (deactivated) copy of windows onto another drive altogether, boot into windows, then pull out the data from the previous boot drive, then wipe out all data from the boot drive, then download windows 10 to the boot drive and reactivate windows. Would this method be feasible? 

Assuming this method is feasible, am I able to install windows on a partially filled up drive without deleting the data already on it? The reason is because I already have some other data (though non-essential, but I would prefer not to lose it). Alternatively, I have a WD My Passport 1TB external drive lying around which I can take out the data. Would that also work?

I'm sorry for so many questions, but I really screwed up this time and I'm thinking of as many scenarios as possible to try to get myself out of this situation. Worse comes to worst, I'm thinking of bringing it to a technician but that's not too ideal for me.

Hopefully, you guys can help me out here. Thanks in advance!