Internet explorer wont open

Anything happen before this started? You can try using a Restore Point to go back to before the issue, but that rarely works to fix anything.

Depending on what you used to check for viruses, you may want to run some other anti-virus programs to check. Malwarebytes is one, another I have used that works well is Avira Antivir, the emergency boot disk they have works well.

Also try to create a new user account, see if it works then.

As a last resort, running a Windows setup in Repair mode could fix this and it will leave your files intact.