You're being pretty un-specific. Some screenshots might be helpful, or any additional information for that matter. Install Avast, if you can, and run a boot-time scan. This will scan your computer directly after POST. Malwarebytes is also some good shit. Between those two, you should get something worked out. If you're not currently running any anti-virus software, shame on you. If you are, remove that shit because it's obviously not doing its intended job.