Windows will not run properly

Ok heres the deal one of our computers does not run with full time protection from viruses while trouble shooting problems i installed NORTONS and did a virus scan it found one Hybris95 plugin or something to this effect. Previously we have had another virus i followed the same protocol. Installed nortons, quarintined items and removed nortons the systems are not supposed to have nortons on full time. Previously there was never a problem like this when i Unistalled nortons, windows will not come up in any mode but safe mode how do i fix this? when trying to go into normal mode a Black screen comes up