Yesterday, I installed Webroot, SpySweeper, I usually am happy with the inbuilt windows defender, but decided to install SpySweeper because of the offer of a free license.
The installation went fine and required a reboot. After rebooting Vista discovered an unknown device and attempted to install drivers for it and coudn't.
Upon investigation the unknown device appeared under "Other Devices" in Device manager. The entry had no identifying strings and looking through the registry I could not find any pointers to the device's origin.
Disabling SpySweeper from starting up with Vista did not solve the problem.
I guess this was the software hook from SpySweeper installing a new device driver to monitor KeyLogger activity. After trying several times to sort the problem out (unsuccessfully) - by disabling KeyLogger shield in WebRoot, and rebooting several times - I uninstalled WebRoot.
On a positive not, their technical support seems very responsive and commendable - I raised a support question via their website and had a response within 10 minutes. It instructed me to uninstall SpySweeper using a cleaning tool and then reinstall the software. I elected not to do this.
My main gripe is with software that installes devices and drives that are unexpected and cause unnecessary hassles and fuck with the basic operation of the OS.