E-machines Computer Have Virus

My mom brought me her e-machines computer today with the complaint that Windows won't load.I think it might have a virus.So I hook it up and turn it on and am greeted with the loading screen before it brings up a windows error screen prompt that looks like a DOS screen.It says how there might have been a power failure or a virus or God knows what, but it gives you three options for proceeding.1) Safe Mode.2) Start with the last known good configuration.3) Start Windows Normally.I tried starting with all three options and it starts to do each one and then restarts and takes me right back to the loading screen before presenting me with the same DOS-looking screen again and the same endless three options.