Ideas about webroot? No.
I use AVG and it can be used for free. The PRO version includes rootkit protection, so it was worth the upgrade to me after using it successfully for so many years.
So, download this for free:
AVG Free - Download installation files & documentation
If WebRoot isn't working, uninstall it (you can reinstall it later), install AVG Free and give it a whirl. Should only take a few minutes, so it's worth the effort.