using product key...help please

[#1]

My daughter has a laptop that has loads of problems, and we have decided the best way to deal with it is to do a reformat and reload (going to be quicker than trying to undo all the faults and problems, also ensure that are all out). Unfortunately the O/S is not on a partition so I need to load from an external source. We don't have discs, though it is a genuine install complete with the little stickers on bottom of laptop.
My question is, can I install from someone else's discs using the licence we have? I have never been in this situation before, so sorry if it seems like a stupid question. Thanks in advance.

[#2]

It will very much depend what version of Windows it is, very precisely, and especially if it's an OEM one, what installation discs you can lay your hands on.
More details required................

[#3]

Thanks HP. I took another look earlier today, and found the factory restore. Not behind a button press combo, as I expected, but hidden away in security settings. So all done now ( apart from a zillion Windows updates). Oh, and removing bloatware, as supplied. A months free MacFee etc. Thanks again.

[#4]

I take it from that it's probably Windows 7 or 8 of some flavour, but which exactly?
Once "clean and tidy" I'd take a full backup system image.

[#5]

Windows 7, 64 bit.
Not too worried about back up, as my daughter just uses it for faecesbook ( no typo there ) and playing cheap or free downloaded games. It will be in same condition in six months so I'm resigned to doing it all again.
I've tried explaining to her about reading the conditions associated with downloading these games, but she just clicks "accept"  then wonders where all the adverts come from, and where her task bar has gone!

[#6]

Glad you're sorted. 
Having a full system image at a known clean point to recover from can be extremely useful, especially if you get a hard disk failure and Factory Restore is no longer possible.
Also have a look to see if there's an option to create recovery and/or reinstall disks. There quite probably is - what brand of PC is it?

[#7]

Thanks. It's an Acer. It does keep asking if I want to create back up discs - but I always click, remind me later. Well have to do that. 

[#8]

Quote from: doris

We don't have discs

Quote from: doris

It does keep asking if I want to create back up discs - but I always click, remind me later.

[#9]

Most OEM laptops / PCs these days will have the secret recovery partition which can be used to reset it to out of the box conditions, it sounds like you found that option.
Windows 8(.1) has an inbuilt option to do this, but I can't comment on it's reliability or effectiveness.

[#10]

Windows 8's inbuilt function in the beta test was very reliable
Not tested the final release or 8.1 to advise further