SSD upgrade fresh install

I bought an SSD and since my computer is very bloated with stuff and with the misalignment issues I've heard about in SSD's, I would like to just install my ssd into my computer and do a fresh install of windows 8.1, which is what the manufacturer shipped with (lenovo g780).

HOWEVER
My question is, since the laptop came with Windows 8.1, is there a way to get a copy of windows 8.1, or would I have to buy a copy? Is there any way to (legally) obtain a copy… Perhaps by making a copy of windows 8.1 onto a bootable flash drive. Or can I download a copy of windows 8.1 online and then re-register my activation code/serial number that came with this computer?

I do not know how these things work. Much help would be appreciated.

You could maybe contact the manufacture of the company and see if you can get a disc, but I doubt it. Most of the time they install the files on some hidden partition on your drive.

You could maybe find a copy of Windows 8 and just use the Serial number for your copy of windows 8. (Its probably on some sticker somewhere on your computer).

I know you could do this, I'm not sure how legal it is.

It is only illegal if you don't use a genuine license key…

If you download Windows 8.1, and you have legally purchased a license key, then you can use that when you install it.

No, I would not recommend making your own copy of windows 8.1, there's legality issues involved with that process. Yes, you would have to buy a copy of windows 8.1. Please refer further to Microsoft's website.