Overwriting a web browser

One of our tech support personnel said that he installed ie5.5 128 bit encryption on a win98 pc. He cloned that pc to 25 other PCs. That was last year. The web browsers on the 25 PCs are now showing ie5.0 with 56bit encryption. He’s saying ie5.5 wasoverwritten or uninstall by another program and ie5.0 was installed. Is this possible? I think he used ghost to clone. I don’t think so. Please note, our users are not in the habit of installing or uninstalling programs.