I know this is an old thread but this happened to me today and i managed to fix it, so maybe someone will find this helpful...
We use Webroot secure anywhere which is managed from a remote console, so unfortunatly it wasn't just a case of add/remove from program files.
Tried removing it from the remote console but that didnt work.
There was a file (not folder) called "Program Files" in C:\
I said yes to rename the folder and it renames the file to "Program Files1" however after every restart the error comes back.
What i done to fix:
Rename the file to "Program Files1.exe" (You might have to enable it so you can view file extensions under folder view and have admin rights)
Restart the computer and go into safe mode.
Once in Safe Mode, open the command prompt as administrator.
Type: cd c:\
Then type: program files1.exe - uninstall
once uninstall is complete make sure there is no other trace of webroot in add/remove programs.
Restart computer and everything should be working ok.
Now re-install the latest version of webroot.