Windows 7 vs 8.1 on a budget Dell laptop

I have a Dell Inspiron i3531-1200BK laptop. It ships with Windows 8.1 with Bing pre-installed. I want to format the hard drive and do a clean install of Windows 7 SP1 Home Premium. Dell officially supports Windows 7 on this model of laptop and provides all necessary drivers and BIOS updates.

Now my questions:

1) Even though I'm doing a clean install of Windows 7, I'd like to retain my copy of Windows 8.1 with Bing, in case I decide to go back. This is an OEM version of Windows 8.1 and does not come with a recovery CD. So, what should I do if I want to retain my copy? Should I create some sort of Windows recovery media? Will my current activation key work? In short, what do I need to do if I decide to go back to Windows 8.1 with Bing?

2) Regarding OS performance... Windows 7 and 8.1 seem to perform more or less identically... with a very slight edge for 8.1 in some cases. The Dell Inspiron i3531-1200BK is a budget laptop, with an Intel Bay Trail N2830 Celeron dual-core, 4GB of RAM and a 500GB hard drive.

Still, I am presuming that a clean install of Windows 7 would have a slight performance edge over an OEM install of Windows 8.1 with the manufacturer's custom-installed software / bloatware... am I more or less right?

3) I may decide not to go with Windows 7 at all and remain with Windows 8.1. A few tweaks, along with Classic Shell make it a very manageable OS.

However, I would still like to do a "spring-clean" re-install of Windows 8.1 every once in a while... does the "Reset" feature wipe the drive clean and perform a new install of Windows 8.1, as most enthusiasts would like, or is there a catch? Are there any steps or precautions I have to take before hitting "Reset"? Note down OEM key? Make my own recovery media etc? Or just click "Reset" and I've got a fresh install of Windows 8.1?

Thanks for taking the time to read through, any input would be very much appreciated! Could you also please chime in your thoughts on OS performance between Windows 7 and 8.1? This is a very low-end laptop with entry-level hardware... so every bit of performance the hardware can squeeze out of the OS is necessary for a fluid experience.

Looking forward to hearing from all of you!

1) As far as I know a microsoft toolkit (One that is also used to illegally activate windows) you can backup your license or you can view the key that is currently used. You may want to look into that

2) To me W8.1 feels a lot snappier and as far as I know W8.1 is a bit better on lower end hardware. Regardless of that though I would still recommend W8.1

3) If you want to do a "Spring-clean" Re-install it's recommended you completely wipe your drives anyway (In which case you WILL need to fill in the key, see 1 for a potential method on how to retain it) for a proper cleaning. The reset feature does what it says: Resets to factory defaults and it should retain your key though I would recommend asking someone else to confirm that first before quoting me on it.

As for W7 vs W8.1, W8.1 has always felt snappier/more responsive to me so I'm not really going back to W7. With classic start obtained via it's just like W7 only snappier.

I recently downgraded to 7 from 8.1 and can't entirely say that it was the right decision. 8.1 overall performs much better than 7, the first thing that comes to mind is file transfers: 8.1 makes 7 look like a pile of turd when it comes to those (if you've tried doing more than one at a time on 7, you'll know what I mean).

The only reason I downgraded to 7 was because some of the programs I use don't seem to like 8.1 all that much.

I would just de-bloat your 8.1 install.
Dont like metro ui? Just set it to boot to desktop.
If anything make a few partitions and dual boot (win 7) or triple (win 7 + linux distro of choice). A linux distro like Mint flys even on low end hardware.

Thanks for all your replies!

I've decided to stick with 8.1 for now. The laptop hard drive has a recovery partition in it, so the reset was very straightforward, no need to input any keys or other recovery options. I took the safe option and created a USB recovery media before the reset, just in case.

From what I've been reading, the Reset function in 8.1 wipes the C partition clean, just like a regular format. The other partitions are the recovery media, OEM partition and EFI partition which are left alone. The program then loads up the recovery media from its partition and installs a fresh copy of Windows 8.1 with Bing. That's good enough for me.

I was pleasantly surprised by the minimal amount of bloatware that Dell includes with this laptop, if any at all! Just Office 2013 trial and Dell's Backup and Recovery software, that's it!

If you need yout licence then download magical jelly bean

Did a little research on that... unfortunately, Microsoft does not provide a Windows 8.1 Single Language with Bing ISO image... so while I could download the Windows 8.1 ISO from Microsoft and use the media creation tool, the product key stored in the BIOS will not work with the ISO and will not install.

The solution to this is contacting the manufacturer, Dell support in my case, and request backup disks containing the Windows 8.1 Single Language with Bing that Microsoft provides to OEMs. I've already contacted them and awaiting reply... however, I don't think I'll get any support since I'm based in Saudi Arabia.

Worst case scenario, I just clean install Windows 7 SP1 Home Premium x64 and get my free upgrade to Windows 10 once its available.