Prior to installing oovoo, no matter which browser your using. Browsing some website on the net can cause your browser to get infected with spyware, malware etc.
Install spybot and run it to scan your system for those infected browser malware, spyware problems. What spybot does is to protect your browser system files from being infected (changed or altered) by various sites that appear on the internet. Installing and Un-installing won't cure the problem.
As for the oovoo tool bar, there is an option when you install oovoo client to turn that feature off. It ASK you if you want to install it YES or NO obviously select NO.