Laptop very slow?!

zyper

For last few days I've been having a progressively slower laptop even though it's only a few weeks old. Lately, I've been getting this message:

''A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the de!!!!!!, or let the script continue.

Script: resource://gre/modules/commonj…scripts/kwift.FFJETPACK.min.js:1''

The internet is unbelievably slow even (both via firefox & ie) though my broadband works fine on my kid's tablet & the laptop in general is very slow in loading stuff like docs, pics, etc & executing commands. I've done a defrag (no joy). I've recently installed then uninstalled avg then replaced that with avast (doubt this is the cause but maybe...)

ANy suggestion to improve performance appreciated as I'm at my tether's end

J_B

Install CCleaner (free version)
https://www.piriform.com/ccleaner/download/standard
Look what's in the start uo part of 'tools' and maybe disable most things (except the AV)
Run the 'cleaner' part and see if that helps .........