FoxTab is one of those browser hijackers, it's hard to believe that it is well spread around by freeware such as FileZilla (SHAME ON YOU FILEZILLA!!!). You can uninstall FoxTab from programs as they suggest, but you will always have a new tab in the foxtab style and certain extensions/addons loaded while "uninstalled".
Solution is simple!
0. Exit Firefox
1. Click Start
2. Click Run
3. Enter "%APPDATA%" without the quotes and hit enter
4. Move the directory "Extensions" to another location
5. Move "addons.json" and "addons.sqlite"
This method works not only for FoxTab but also for a lot of other malicious addon, extensions, browser hijackers.