Hi
What antivirus/security software you got?
If you can, create a new user called Backup, reboot, then login as the new user, install malwarebytes and update it and then run it (Full scan).
Then goto the Malware directory and copy the mbam.exe and paste it. Then rename the copied one to iexplore.exe
Next logoff and login as the infected user.
To run Malwarebytes in the infected user, you need to goto the malwarbytes folder and run the iexplore.exe as that type of trojan or virus stop most exe's from running.
You can also get this and run it, but use as a last resort.
Let me know how you get on and when you normally on as I am UK time