There is a Pentium 4 2,4 GHz that uses Hyper-threading. This is the Northwood series. Since may 2003 every Pentium 4 CPU uses Hyper-Threading, according to this wiki:

List of Intel Pentium 4 microprocessors - Wikipedia, the free encyclopedia

However since my CPU uses C1 stepping it cannot be a model that uses Hyper-threading since all Northwood type CPU´s with Hyper-threading use D1 stepping. (see wiki above)

So I´m sorry for wasting your time. I must have been mistaken about the Hyper-Threading.

But anyway thanks for trying to help me out!