My PC was bought just before Windows 10 came on the scene.  It originally had Windows 7 professional installed but has since been upgraded to Windows 10.  Its always run well until the last month or so and has been getting progressively slugish.  I don't think there's any viruses - but you never know (virus software is just windows defender plus malwarebytes premium).  Its a reasonably grunty machine - i7 processor, 32GB Ram and solid state disk containing the operating system

I decided that I wanted to start again with a new install so went through the Win10 recovery process.  After a bit of thought, I decided to use the windows Fresh Start which keepsall of my personal files and some of the windows settings.  

Unfortunately, after only a day, the PC has gone back to its old ways - possibly because some of my old settings have been retained... maybe.

I thinking now of doing a Reset, but am concerned that this may reinstall the original Windows 7 - and then I'd have to go through the upgrade process to Wi10, possibly having to pay..

So, my questions are, if anyone can help:

- if I do a reset, will I go back to the original Win7 - and if I subsequently upgrade to Win10 will I have to pay for another subscription

- is there a better way of getting a completely clean install of Win 10 - again without having to pay for another subscription.

All my date is well backed up, so I don't need to be concerned about this.

Any help much appreciated.