Windows10 is an Operating System NOT a Anti Virus Program. However Windows 10 does have it's own Anti Virus Program called Windows Defender. And If you have a Virus Windows Defender should have detected it.
You may not have a Virus, Because Not all Malware is a Virus. You should install the free version of Malwarebytes.
First run Malwarebytes in SAFE MODE. It will find most of the adware and junkware out there. It is NOT a true AV but most infection can be stopped by the free version.
This link explains how to get into safe mode for Windows 7,8 & 10
If Malwarebytes does not find anything then try ESET online scanner to check for a true virus. The first link is the online scanner. You need to USE IE while in the safe mode with networking to run it. The second link explains it.
If these do not work post your results and I can post a more aggressive way of looking for the malware.
Grab a free copy of malwarebytes at http://www.malwarebytes.org. Install and run the scan. Clean off anything it finds.
If that doesn't completely solve the issue, you should now be able to do a system restore to a point prior to the problem (unless you've let it sit for a long time and that restore point is no longer available).
If you still can't get it, I recommend using a service to clean your PC, like http://www.cleanourcomputer.com they will remotely access your PC while you watch and clean it up!
If your resident antivirus hasn't blocked it download from here http://www.avg.com/gb-en/avg-rescue-cd AVG rescue disk and burn it to a CD. You may need a working computer if yours is badly infected. Boot off the CD and follow the prompts. After that your computer should be clean.
Once your computer is up and running I would also download Malwarebytes antimalware from bleeping computers
Run it to check for any malware that AVG missed
Avast anti virus does job for me