What do I do next? Installing windows 10.

[ayeitsbagio]

This is my first time doing a fresh install of windows 10 and building a PC and Idk what to expect. I'm upgrading everything for my PC EXCEPT the GPU and CPU. My HDD has OS Win10 installed correct? (Or am I an idiot to think that)

What steps do I take in order to keep my old files in my HDD?

This is the scenario. Build new PC > Place USB with windows ISO > Install windows 10
Is it safe to connect my HDD with old OS and is it possible to boot using the USB instead of the HDD while it's connect to the mobo?
After the new OS is installed, do I just delete the old OS folder? or will it be automatically over written.
Or is my concept all wrong? Can someone enlighten me with all this?
I've never upgraded/built a pc my entire life so everything is new to me. Pardon the noobiness.

(Not so)TL;DR
Can I boot from USB OS Installation ISO file while HDD with OS W10 is connected to mobo?
Can I install new OS W10 while HDD with old OS W10 is connected to MOBO and delete old OS after new OS is installed to keep old files?


Edit: I've backed up my personal essentials not everything on an external drive and I've backed everything up on a Backblaze online storage account.

 

[USAFRet]

You really, really need to copy your personal stuff off to another drive.

A reinstall of the OS on a drive already containing a Windows OS is a risky deal in trying to keep your stuff.
And installing the new OS WILL wipe out that entire partition. There will be no old Windows folder to delete.

 

[ayeitsbagio]

You really, really need to copy your personal stuff off to another drive.

A reinstall of the OS on a drive already containing a Windows OS is a risky deal in trying to keep your stuff.
And installing the new OS WILL wipe out that entire partition. There will be no old Windows folder to delete.

Yeah the only thing important to me are documents, pics, and vids but I've backed those up on an external HDD and everything else on an online storage.

So when I boot from the USB ISO installation, the install will automatically be placed in my HDD and format it?

 

[USAFRet]

You really, really need to copy your personal stuff off to another drive.

A reinstall of the OS on a drive already containing a Windows OS is a risky deal in trying to keep your stuff.
And installing the new OS WILL wipe out that entire partition. There will be no old Windows folder to delete.

Yeah the only thing important to me are documents, pics, and vids but I've backed those up on an external HDD and everything else on an online storage.

So when I boot from the USB ISO installation, the install will automatically be placed in my HDD and format it?

OK, so you have everything critical backed up elsewhere and offline.

Have you linked your OS license to your MS account? This is probably required due to the all new hardware.
Read here:
https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change
http://www.tomshardware.com/forum/id-3164428/windows-build-1607-activation.html

 

[ayeitsbagio]

You really, really need to copy your personal stuff off to another drive.

A reinstall of the OS on a drive already containing a Windows OS is a risky deal in trying to keep your stuff.
And installing the new OS WILL wipe out that entire partition. There will be no old Windows folder to delete.

Yeah the only thing important to me are documents, pics, and vids but I've backed those up on an external HDD and everything else on an online storage.

So when I boot from the USB ISO installation, the install will automatically be placed in my HDD and format it?

OK, so you have everything critical backed up elsewhere and offline.

Have you linked your OS license to your MS account? This is probably required due to the all new hardware.
Read here:
https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change
http://www.tomshardware.com/forum/id-3164428/windows-build-1607-activation.html

Yes I have linked it and spoke to a Microsoft tech stating they will troubleshoot for me when I'm in the activation key sequence of the boot.

 

[USAFRet]

Yes I have linked it and spoke to a Microsoft tech stating they will troubleshoot for me when I'm in the activation key sequence of the boot.

OK then.
The Activation Troubleshooter should work on its own, but if not, call MS>

So, to the install...

You've created the USB install
Have only the one HDD connected. Disconnect ALL other drives.
Boot from your Win 10 USB.
When it asks for the license key, select "I don't have a product ID", and proceed on
When is asks 'where to install to', select Custom.
You'll be presented with a list of ALL existing partitions.
Select ea h one, DELETE
Leaving one large blank space.
Create a partition, using that whole space.
Continue, letting the OS create what it needs.

 

[ayeitsbagio]

Yes I have linked it and spoke to a Microsoft tech stating they will troubleshoot for me when I'm in the activation key sequence of the boot.

OK then.
The Activation Troubleshooter should work on its own, but if not, call MS>

So, to the install...

You've created the USB install
Have only the one HDD connected. Disconnect ALL other drives.
Boot from your Win 10 USB.
When it asks for the license key, select "I don't have a product ID", and proceed on
When is asks 'where to install to', select Custom.
You'll be presented with a list of ALL existing partitions.
Select ea h one, DELETE
Leaving one large blank space.
Create a partition, using that whole space.
Continue, letting the OS create what it needs.

Alright. Thank you so much for the help! I appreciate the time you gave into directing me in the right process. Everything is clear now. Thank you very much!

 

[USAFRet]

After seeing your other thread and realizing it is a preinstalled OEM Win 10....linking the OS and using on new hardware may not be applicable.

If it fails to activate on the new hardware, your only 2 recourses are to ask Microsoft, or buy a new OS for your new hardware.