Maximum PC

Hello Everyone,

I've a BIG problem. My computer is buggy as heck and I'd like to restore it to 'factory' settings as this was recommended to me. I have a Gateway SX2801-07e with Windows 7. I know very little re computers.
What do I need to back (anything?) up? I don't want to back up and reinstall all this malware. I, of course, have a keyboard, monitor and mouse hooked up but also a printer, router and headphones/mic. I have the CD that came with the router only, not the one from the printer or the headphones (if there was one w/ headphones...?) How is that sort of thing resolved? There must be a way because it is surely a common problem. Also, will Windows 7 go bye bye? I don't want to make of my computer a blank slate, I'd just like it to perform the way it used to. Even 2 weeks ago it was multiples of times better than it is now.
So, what should I back up and HOW do I back it up? Please be super simple as I'm pretty ignorant with tech. Also, I obviously don't want to back up anything that might be contaminated, so to speak, with whatever is afflicting my PC. Pictures I do NOT need backed up.
I really appreciate whoever takes the time and effort to take me through this step by step. There are Youtube videos but none for the exact computer with the same operating system as mine. Also, please only answer if you really know what you're talking about. I can't afford to lose this computer. Literally. If it 'dies' I'd likely have to wait months to get a new one.

Thanks!

If that didn't work...

• Restart the computer
• Keep pressing F8 before Windows loads, but after POST (when the logo shows up).
• When a menu pops up, select "Repair this computer"
• Once in the repair environment, there should be selection for factory reset.