I would first try to RESET IE.

In IE > Tools > Internet Options then the Advanced tab, hit the RESET button. This should remove all add-ons and 'may' reset toolbars back to default.

If that fails, the next option is anti-virus and anti-malware scans. Scan with the installed anti-virus scanner, then download, install, update and run, one after the other, the free versions of Malwarebytes Anti-malware and SUPERAntiSpyware