something has modified your browser as plugin. Its probably resident in your regsitry, and uses an add-on, or exploitable active x or com driver.
check to see if your on an NT platform. If you are and did NOT activiate it yourself, you were either remoted or something you downloaded activated it. Its most likely modified your boot record, and if you just terminate it its going to cause your boot to fail.
Without specifices and my lack of experience, i just put it like this, 3 things you need to do, maybe 4.
using wmi determine how the unwanted issue communicates, and block it wmi firewall administarton.
determine the rogue module, sandbox it somehow, or disactivate it temporarily, perhaps change its name and refresh the process.
you COULD create a do nothing dummy file using the same name and file type, let it load run and do nothing, as a a crutch, while you physically remove the problem.
Edit all instances in the registry that ONLY pertain to unwanted problem, not just complete deletion of everything.
find the encoded regsitry key that it resides in get rid of it.
do a registry fix, to unrefference any registry changes you made, read them closely to see if you interupted something you need or not.
run a boot repair or fix.
better idea all together, is save a restore point, so if you explode your system you can just do a restore and try something different.