Reports Wrong Disk Size

I used linux upt to image some win98 machines. The original machine had a 8g hard drive and the ones I imaged had 4g hard drives. The imaged machines now think they have 8’s in windows(98) although the Bios reports the correct size. I had this happen a few years ago and found a solution but have forgotten what it was. I do know that it didn’t involve reformatting or partition software. It was a reg hack or something similar. Any ideas out there?