At this point the virus, and it was a virus no doubt, has done irreparable damage to the operating system, and possible the hard drive. You will need an operating system disc, no way around that. Once you have the disc, then you will need to reformat the hard drive using the full NTFS format, not the quick format, to ensure total deletion of the virus, and install a new operating system. If the hard drive won't format or if you have any issues during or after the install, then the hard drive has or is failing and will need replaced. If you need any futher asststance with this just ask.