Norton doesn't have a free version and I don't know how ad blocking programs work - I'm more interested that they do.
I could install Adguard but unless I land on an unsafe site, I still wouldn't know how it reacts.
As for a slow IE, that can be because of a build up of the temporary Internet file cache.
At the end of each session I use CCleaner, mainly with default settings other than unchecking the box to clear the Mini Dump files and I have IE set to delete everything on close.
While I use SuperAntiSpyware's setting to Delete Windows Temp files during its scan, this can be done by going Start - type %temp% and press enter.
If it's highly populated then click on Organize - Select all - Organize - Delete - Confirm - check the box and click on Skip.
This maintenance ensures the machine doesn't get bogged down.
Add-ons can also have an impact on the performance of IE, so you should check to see which of those you really need and resetting IE to defaults can get rid of some of the spurious ones.
Resetting IE to defaults also quite often resolves any problems with IE.
When you check all of the delete boxes, you may have to reset your home page as well as moving Google back up as the default search provider as it tends to default Bing, if that is your choice and then check the box to Prevent changes to the search provider.
I also click on the Delete history/Settings button of the General page in Internet options and change that to 100MB and drop the History down to 0 days.
MS has a Fixit for IE which you can run, but only applies to XP through to Win 8.0 and scrolling down the page will show what it is intended to fix.
https://support.microsoft.com/en-gb/mats/ie_performance_and_safetyTo see if it is your add-ons that is the cause then you can run IE without them by going Start - (I'm using Win 7) - All Programs - Accessories - System Tools - Internet Explorer (No Add-ons).
Clicking on the home page icon will give you your home page for normal browsing and if that improves its performance, restart IE then manually disable all add-ons, reinstating one at a time until its performance degrades again, but if you have done all of the previous, this shouldn't be necessary.