Webroot Spy Sweeper Ineffective software, almost impossible to get rid of. Internet

About a year ago, I purchased Webroot antivirus to protect my computer from viruses and other malware.  After a few months, i got a virus.  I cleaned it off, and marked it up to the fact that no software is perfect.  A little later, I got another virus.  This time I got upset, and began to look for another antivirus.  I found a new antivirus that I wanted to try, and I downloaded and paid for it.  I deleted the Webroot and ran a uninstall utility provided by Webroot.  After the uninstall, I could find no trace of the Webroot program on my computer.  

A couple of months later, I began having major problems with my computer.  upon investigating, I found that the Webroot program had reinstalled itself.  Despite the uninstall utility, somewhere on my computer, a file was lurking somewhere. Again, i uninstalled the Webroot program and ran the uninstall utility, and this time even ran safemode with command to search for any other files and delete them.  I could not find and evidence of any Webroot files.  Lo and behold, a couple of months later, like Jason from the dead, here comes the Webroot program again, reinstalling itself again.  This has continued on and off for almost a year.  This Webroot stuff is much nastier than the viruses it is supposed to be preventing.  It is almost impossible to get rid of entirely.  I have spent probably 80 hours over the last 9 months trying to get rid of it.  I have no idea where it hides on my computer.  I have looked and looked.  This evil stuff is like a zombie, just keeps coming back from the dead.  I have just finished cleaning it up again, but I have no confidence at all that it will stay cleaned up. This company needs a class action lawsuit filed against it for harassment of customers who change antivirus companies.