Booting into a Black screen

Recently I have had a virus/trojan that prevented me from booting, (or so I thought)so I removed the drive and replace with a new one.

My PC is virus protected but it seems to have the same problem as before “It keeps booting into a black screen” I will boot okay in safe mode. but to get it up and running will takes several attempts of re-booting before windows XP will load properly.

I have had to disable the floppy drive as when the machine was trying to boot it accessed the floppy(I have turned off “Floppy seek” in the BIOS.

Could it be that my power supply (450wt) is not performing as it should, someone mentioned “Boot Logging” that this may be causing it

Any help would be appreciated