Welcome to Anvisoft forum. I am sorry to hear that you still experience the snap.do redirect virus.
It must be that some items related to snap.do still exit on your computer, and start automatically when you boot your PC, and then change your browser setting once again.
Please go to your control panel and check once again if any program named snap.do or resoft, if you find any, please make sure to uninstall.
If you can not find any suspicious in your control panel, please just ignore the step and go to check your startup menu to prevent it coming back again.
To do that, please follow tips below:
1. Download Anvi Startup Booster and install it: http://www.anvisoft.com/startup-booster.html
2. After you get Anvi Startup Booster installed, please go to Startup Tab, find setup that’s belonging to snap.do, and then click the drop-down menu button, select the Location from the list, and you will be forwarded to the program folder of snap.do, please make sure to delete all file located under the snap.do.
Expand the drop down menu of Setup again, click on “Delete” button again to remove the snap.dofrom the startup menu.
Should you have any problem, please feel free to contact us.