Hello,
First reboot into Safe Mode with Networking.
http://www.sevenforums.com/tutorials/69585-safe-mode.html
Go to Control Panel, Uninstall a Program. Check to see if MSE appears in the list. If it does uninstall it. Close Window.
Open Browser and download free 30-day trial of Norton 360, update and run a full scan. When offered to activate the other features of Norton, just click on remind later. I don't know your location or ISP, but Comcast provides Norton 360 free with subscription to their service.
Best Free Antivirus - Download Norton 360 Free Trial Software
If you have trouble running Norton in Normal Mode, the reboot back into Safe Mode with Networking and run it.
While still in Safe mode with Networking download JRT, Save As, to your Desktop. Don't run yet.
https://www.malwarebytes.com/junkwareremovaltool/
Next download Adwcleaner, Save As, to your Desktop. Don't run yet.
https://toolslib.net/downloads/viewdownload/1-adwcleaner/
Reboot into Normal Mode and run each of these cleaners.
Finally, download CCleaner, repeat running scans until it doesn't find anything to remove. Be sure to use the Back Up feature when cleaning the registry.
http://www.sevenforums.com/tutorials/306648-ccleaner-delete-junk-files.html
Afterwards go back into "Uninstall a Program" and make sure MSE is removed. Or it may conflict with Norton.
Let us know how you Computer is running afterwards.
If you don't want Norton after the cleaning is done. Download the Norton 360 removal tool.
Norton Removal Tool Download
Then go download a new copy of MSE.
https://www.microsoft.com/en-us/download/details.aspx?id=5201
Also, download and install the free version of Malwarebytes and run a full scan.
https://www.malwarebytes.com/mwb-download/
Hope this helps'
John