It's quite easy to remove the mystart Incredibar.
Here is my tips:
1. Please go to the Start Menu. Select Control Panel → Add/Remove Programs.
If you are using Windows Vista or Windows 7, select Control Panel → Uninstall a Program.
2. Search for mystart by incredibar in the list. Select the program and click Remove button.
If you are using Windows Vista/7, click Uninstall up near the top of that window.
3. Change your browser setting:
Open Mozilla Firefox. Click on the magnifying glass search icon and select Manage Search Engines...
2) Choose Search Results from the list and click Remove to remove it. Click OK to save changes.
3) Go to Tools → Options. Under the General tab reset the startup homepage or change it to google.com, etc.
You can also refer to steps listed here
http://support.mozill...n-US/questions/905782