I'm surprised you had these problems using Windows XP. I found that to be the most reliable of all the Windows versions I have had the misfortune to have to use.
I certainly would not upgrade to W8 (I'm not sure you can any more, anyway). I have that on one of my machines at the moment. I have constant trouble with it (many along the lines you just described - losing internet connectivity etc.). I once tried upgrading to W10. Wish I'd never bothered:
http://www.theanswerbank.co.uk/Technology/Question1504855.html
I've lost my wireless driver (for no reason), my Hub is not recognised (for no reason) and all manner of things.
Mrs NJ has a newer machine with W10 and it fares a little better but for how long is anybody's guess. It now regularly "loses" its wireless driver and it has to be repaired or reinstalled:
http://www.theanswerbank.co.uk/Technology/Question1514446.html
My Microsoft Office has to be repaired at least once a week. Excel workbooks "lose" all their macros; files that are closed still register as open (making it impossible to reopen or save them); Outlook spontaneously closes and will not reopen (because it thinks it is already open).
None of these problems seem to have any rhyme or reason to them. You shut the lid, open it up two hours later to find you cannot access the internet, your e-Mail will not send/receive or worse.
If you do opt for W10 bear in mind that Microsoft now dictates that you WILL receive all the "updates" (aka fault fixes) it thinks fit. You can delay them, but not avoid them forever (unless you undertake some complex coding which I have neither the ability nor will to do). Prepare for your machine to be down for some time for many of these.
Fortunately we have on AB 'Chico and others who help enormously to cure all these problems. But Microsoft are getting away with murder by selling products which are quite simply not fit for purpose.
Rant over :-)