If you are seeing issues with one device and not another, it's unlikely to be the wireless channel, but more likely the wireless adaptor on the laptop. That assumes that you've tested the iPad from the same location as the laptop.
Possible suspect is the wireless adaptor in the laptop - is it a fairly new laptop or have you upgraded an old one to Windows 8.1? It would be worth checking for updated drivers.
Another way you could check the laptop would be to take it to your son's house and see if you have the same problems connecting to his router. That also assumes your son lives close enough to home for you to try that. If not, if you're on good terms with your neighbours, perhaps one of them would be up for letting you try theirs?
From September 2001 on BTopenworld Home 500/Home 1000/Home 2000. Then ADSLMax on <n>ildram. Moved to ADSL2+ from ADSL24. I'm now with plusnet on FTTC since 28/05/2014 and loving it... I'm not saying who I work for. Any opinions expressed here are my own.