This Windows 2000 system has the System Security virus or malware -- it hijacks the internet browser and redirects to different sites, pops up warnings, etc. I have been unable to install Malwarebytes, HiJack This, etc., even after renaming them to something different. I am not able to install in either regular or safe mode. I saw the program running under Task Manager and ended the process, which has kept it from popping up repeatedly, however I am unable to install anything. Spybot was on this computer and runs ok, but says it doesn't find anything. Any help you can provide will be appreciated!