You have got yourself into a bit of a pickle. :)
First the cpu. It looks from your posting as if the fsb of the cpu has reset it's self to 100mhz. This would give you 100mhz X 12.5 ( multiplier ) giving you a clock speed of 1.25Ghz. If you reset in the bios to a 166fsb this would give you 166Mhz X 12.5 giving you a clock speed of about 2.08Ghz. This is near your true speed.
Now to look at the hard drive. When the machine post's, when it is booting up, what size is shown in the post screen. Or you could enter the bios and look at standard cmos settings. What size is displayed for the primary master hard drive? If it says 120gig, then this ghost writer may have done something to the drive, i have never come across ghost writer.
If it did show as 120gig in the bios then I would start the computer with an old 98 boot disk and see what the size is in fdisk. I would also look to see if the drive has been partitioned in anyway.